diff --git a/.gitignore b/.gitignore
index 0d945cd..73f211a 100644
--- a/.gitignore
+++ b/.gitignore
@@ -91,3 +91,9 @@ Icon
 *.dmg
 build
 test*
+!tests/
+!tests/*.cpp
+
+# AW
+.aw/
+CLAUDE.md
diff --git a/CMakeLists.txt b/CMakeLists.txt
index b3b55f4..384b3dc 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -4,6 +4,8 @@ project(Clouck)
 set(CMAKE_CXX_STANDARD 17)
 set(CMAKE_CXX_STANDARD_REQUIRED ON)
 
+include(CTest)
+
 # Find Qt6
 find_package(Qt6 REQUIRED COMPONENTS Core Widgets)
 
@@ -23,12 +25,14 @@ qt6_standard_project_setup()
 # Sources
 set(SOURCES
     main.cpp
+    autostart_manager.cpp
     clock_widget.cpp
     config_manager.cpp
     window_helper.cpp
 )
 
 set(HEADERS
+    autostart_manager.h
     clock_widget.h
     config_manager.h
     window_helper.h
@@ -73,3 +77,27 @@ install(TARGETS Clouck
     RUNTIME DESTINATION bin
     BUNDLE DESTINATION bin
 )
+
+if(BUILD_TESTING)
+    find_package(Qt6 REQUIRED COMPONENTS Test)
+
+    qt6_add_executable(ConfigManagerTest
+        tests/config_manager_test.cpp
+        config_manager.cpp
+        config_manager.h
+    )
+    target_include_directories(ConfigManagerTest PRIVATE ${CMAKE_CURRENT_SOURCE_DIR})
+    target_link_libraries(ConfigManagerTest PRIVATE Qt6::Core Qt6::Gui Qt6::Test)
+
+    add_test(NAME ConfigManagerTest COMMAND ConfigManagerTest)
+
+    qt6_add_executable(AutoStartManagerTest
+        tests/autostart_manager_test.cpp
+        autostart_manager.cpp
+        autostart_manager.h
+    )
+    target_include_directories(AutoStartManagerTest PRIVATE ${CMAKE_CURRENT_SOURCE_DIR})
+    target_link_libraries(AutoStartManagerTest PRIVATE Qt6::Core Qt6::Test)
+
+    add_test(NAME AutoStartManagerTest COMMAND AutoStartManagerTest)
+endif()
diff --git a/autostart_manager.cpp b/autostart_manager.cpp
new file mode 100644
index 0000000..e870327
--- /dev/null
+++ b/autostart_manager.cpp
@@ -0,0 +1,79 @@
+#include "autostart_manager.h"
+
+#include <QCoreApplication>
+#include <QDir>
+#include <QFileInfo>
+#include <QSaveFile>
+#include <QStandardPaths>
+#include <QXmlStreamWriter>
+
+namespace
+{
+const QString launchAgentLabel = QStringLiteral("com.clouck.clock");
+}
+
+bool AutoStartManager::enableForCurrentApplication()
+{
+#ifdef Q_OS_MAC
+    const QString agentPath = launchAgentPath();
+    if (agentPath.isEmpty())
+    {
+        return false;
+    }
+
+    const QFileInfo agentFileInfo(agentPath);
+    if (!QDir().mkpath(agentFileInfo.absolutePath()))
+    {
+        return false;
+    }
+
+    QSaveFile agentFile(agentPath);
+    if (!agentFile.open(QIODevice::WriteOnly | QIODevice::Text))
+    {
+        return false;
+    }
+
+    agentFile.write(launchAgentContents(QCoreApplication::applicationFilePath()).toUtf8());
+    return agentFile.commit();
+#else
+    return false;
+#endif
+}
+
+QString AutoStartManager::launchAgentContents(const QString &executablePath)
+{
+    QString contents;
+    QXmlStreamWriter writer(&contents);
+    writer.setAutoFormatting(true);
+    writer.writeStartDocument();
+    writer.writeDTD("<!DOCTYPE plist PUBLIC \"-//Apple//DTD PLIST 1.0//EN\" \"http://www.apple.com/DTDs/PropertyList-1.0.dtd\">");
+    writer.writeStartElement("plist");
+    writer.writeAttribute("version", "1.0");
+    writer.writeStartElement("dict");
+
+    writer.writeTextElement("key", "Label");
+    writer.writeTextElement("string", launchAgentLabel);
+    writer.writeTextElement("key", "ProgramArguments");
+    writer.writeStartElement("array");
+    writer.writeTextElement("string", executablePath);
+    writer.writeEndElement();
+    writer.writeTextElement("key", "RunAtLoad");
+    writer.writeEmptyElement("true");
+
+    writer.writeEndElement();
+    writer.writeEndElement();
+    writer.writeEndDocument();
+
+    return contents;
+}
+
+QString AutoStartManager::launchAgentPath()
+{
+    const QString homePath = QStandardPaths::writableLocation(QStandardPaths::HomeLocation);
+    if (homePath.isEmpty())
+    {
+        return QString();
+    }
+
+    return QDir(homePath).filePath("Library/LaunchAgents/" + launchAgentLabel + ".plist");
+}
diff --git a/autostart_manager.h b/autostart_manager.h
new file mode 100644
index 0000000..f0ab9ed
--- /dev/null
+++ b/autostart_manager.h
@@ -0,0 +1,16 @@
+#ifndef AUTOSTART_MANAGER_H
+#define AUTOSTART_MANAGER_H
+
+#include <QString>
+
+class AutoStartManager
+{
+public:
+    static bool enableForCurrentApplication();
+    static QString launchAgentContents(const QString &executablePath);
+
+private:
+    static QString launchAgentPath();
+};
+
+#endif // AUTOSTART_MANAGER_H
diff --git a/clock_widget.cpp b/clock_widget.cpp
index 94e2bd0..51392fd 100644
--- a/clock_widget.cpp
+++ b/clock_widget.cpp
@@ -2,13 +2,14 @@
 #include "config_manager.h"
 #include "window_helper.h"
 #include <QVBoxLayout>
-#include <QTime>
+#include <QDateTime>
 #include <QColorDialog>
 #include <QFontDialog>
 #include <QInputDialog>
 #include <QMessageBox>
 #include <QApplication>
 #include <QScreen>
+#include <QTimeZone>
 
 ClockWidget::ClockWidget(QWidget *parent)
     : QWidget(parent), m_dragging(false), m_resizing(false), m_resizeBorder(5)
@@ -48,11 +49,14 @@ ClockWidget::~ClockWidget()
 
 void ClockWidget::setupUI()
 {
-    m_timeLabel = new QLabel(this);
-    m_timeLabel->setAlignment(Qt::AlignCenter);
+    m_primaryTimeLabel = new QLabel(this);
+    m_secondaryTimeLabel = new QLabel(this);
+    m_primaryTimeLabel->setAlignment(Qt::AlignCenter);
+    m_secondaryTimeLabel->setAlignment(Qt::AlignCenter);
 
     QVBoxLayout *layout = new QVBoxLayout(this);
-    layout->addWidget(m_timeLabel);
+    layout->addWidget(m_primaryTimeLabel);
+    layout->addWidget(m_secondaryTimeLabel);
     layout->setContentsMargins(10, 10, 10, 10);
 }
 
@@ -74,6 +78,12 @@ void ClockWidget::createMenu()
     QAction *fontSizeAction = new QAction("Set Font Size", this);
     connect(fontSizeAction, &QAction::triggered, this, &ClockWidget::changeFontSize);
 
+    QAction *primaryTimeZoneAction = new QAction("Set First Time Zone", this);
+    connect(primaryTimeZoneAction, &QAction::triggered, this, &ClockWidget::changePrimaryTimeZone);
+
+    QAction *secondaryTimeZoneAction = new QAction("Set Second Time Zone", this);
+    connect(secondaryTimeZoneAction, &QAction::triggered, this, &ClockWidget::changeSecondaryTimeZone);
+
     QAction *resetAction = new QAction("Reset Settings", this);
     connect(resetAction, &QAction::triggered, this, &ClockWidget::resetSettings);
 
@@ -86,6 +96,9 @@ void ClockWidget::createMenu()
     m_contextMenu->addAction(bgColorAction);
     m_contextMenu->addAction(fontSizeAction);
     m_contextMenu->addSeparator();
+    m_contextMenu->addAction(primaryTimeZoneAction);
+    m_contextMenu->addAction(secondaryTimeZoneAction);
+    m_contextMenu->addSeparator();
     m_contextMenu->addAction(resetAction);
     m_contextMenu->addAction(quitAction);
 }
@@ -179,8 +192,8 @@ void ClockWidget::contextMenuEvent(QContextMenuEvent *event)
 
 void ClockWidget::updateTime()
 {
-    QString currentTime = QTime::currentTime().toString("HH:mm:ss");
-    m_timeLabel->setText(currentTime);
+    m_primaryTimeLabel->setText(formattedTime(m_primaryTimeZoneId));
+    m_secondaryTimeLabel->setText(formattedTime(m_secondaryTimeZoneId));
 }
 
 void ClockWidget::toggleAlwaysOnTop()
@@ -240,6 +253,16 @@ void ClockWidget::changeFontSize()
     }
 }
 
+void ClockWidget::changePrimaryTimeZone()
+{
+    changeTimeZone(true);
+}
+
+void ClockWidget::changeSecondaryTimeZone()
+{
+    changeTimeZone(false);
+}
+
 void ClockWidget::resetSettings()
 {
     int ret = QMessageBox::question(this, "Reset Settings", "Are you sure you want to reset all settings?");
@@ -304,6 +327,8 @@ void ClockWidget::loadSettings()
     m_backgroundColor = m_configManager->backgroundColor();
     m_fontSize = m_configManager->fontSize();
     m_alwaysOnTop = m_configManager->alwaysOnTop();
+    m_primaryTimeZoneId = m_configManager->primaryTimeZoneId();
+    m_secondaryTimeZoneId = m_configManager->secondaryTimeZoneId();
 
     // Restore window position and size
     QPoint windowPos = m_configManager->windowPosition();
@@ -344,6 +369,8 @@ void ClockWidget::saveSettings()
     m_configManager->setAlwaysOnTop(m_alwaysOnTop);
     m_configManager->setWindowPosition(pos());
     m_configManager->setWindowSize(size());
+    m_configManager->setPrimaryTimeZoneId(m_primaryTimeZoneId);
+    m_configManager->setSecondaryTimeZoneId(m_secondaryTimeZoneId);
 
     // Save to XML file
     if (!m_configManager->saveSettings())
@@ -357,6 +384,7 @@ void ClockWidget::updateStyleSheet()
     QString styleSheet = QString(
                              "QLabel { "
                              "color: %1; "
+                             "font-family: 'SF Pro Rounded'; "
                              "font-size: %2pt; "
                              "font-weight: bold; "
                              "background-color: %3; "
@@ -367,6 +395,65 @@ void ClockWidget::updateStyleSheet()
                                   QString::number(m_fontSize),
                                   m_backgroundColor.name(QColor::HexArgb));
 
-    m_timeLabel->setStyleSheet(styleSheet);
+    m_primaryTimeLabel->setStyleSheet(styleSheet);
+    m_secondaryTimeLabel->setStyleSheet(styleSheet);
     setStyleSheet(QString("background-color: transparent;"));
 }
+
+void ClockWidget::changeTimeZone(bool primaryClock)
+{
+    QStringList timeZoneIds;
+    for (const QByteArray &timeZoneId : QTimeZone::availableTimeZoneIds())
+    {
+        timeZoneIds.append(QString::fromUtf8(timeZoneId));
+    }
+
+    const QString currentTimeZoneId = primaryClock ? m_primaryTimeZoneId : m_secondaryTimeZoneId;
+    const int currentIndex = timeZoneIds.indexOf(currentTimeZoneId);
+    bool accepted = false;
+    const QString selectedTimeZoneId = QInputDialog::getItem(
+        this,
+        primaryClock ? "Set First Time Zone" : "Set Second Time Zone",
+        "Time Zone:",
+        timeZoneIds,
+        currentIndex < 0 ? 0 : currentIndex,
+        false,
+        &accepted);
+
+    if (!accepted)
+    {
+        return;
+    }
+
+    if (primaryClock)
+    {
+        m_primaryTimeZoneId = selectedTimeZoneId;
+        m_configManager->setPrimaryTimeZoneId(selectedTimeZoneId);
+    }
+    else
+    {
+        m_secondaryTimeZoneId = selectedTimeZoneId;
+        m_configManager->setSecondaryTimeZoneId(selectedTimeZoneId);
+    }
+
+    if (!m_configManager->saveSettings())
+    {
+        qDebug() << "Failed to save time zone settings to config.xml";
+    }
+    updateTime();
+}
+
+QString ClockWidget::formattedTime(const QString &timeZoneId) const
+{
+    const QTimeZone timeZone(timeZoneId.toUtf8());
+    if (!timeZone.isValid())
+    {
+        qWarning() << "Invalid time zone configured:" << timeZoneId;
+        return QString("Invalid time zone\n%1").arg(timeZoneId);
+    }
+
+    const QDateTime timeInZone = QDateTime::currentDateTimeUtc().toTimeZone(timeZone);
+    const QString cityName = QString::fromUtf8(timeZone.id()).section('/', -1).replace('_', ' ');
+    return QString("%1\n%2")
+        .arg(timeInZone.time().toString("HH:mm"), cityName);
+}
diff --git a/clock_widget.h b/clock_widget.h
index db11cef..afac2bd 100644
--- a/clock_widget.h
+++ b/clock_widget.h
@@ -31,6 +31,8 @@ private slots:
     void changeFontColor();
     void changeBackgroundColor();
     void changeFontSize();
+    void changePrimaryTimeZone();
+    void changeSecondaryTimeZone();
     void resetSettings();
     void quitApplication();
 
@@ -40,8 +42,11 @@ private:
     void loadSettings();
     void saveSettings();
     void updateStyleSheet();
+    void changeTimeZone(bool primaryClock);
+    QString formattedTime(const QString &timeZoneId) const;
 
-    QLabel *m_timeLabel;
+    QLabel *m_primaryTimeLabel;
+    QLabel *m_secondaryTimeLabel;
     QTimer *m_timer;
     QMenu *m_contextMenu;
 
@@ -61,6 +66,8 @@ private:
     QColor m_backgroundColor;
     int m_fontSize;
     bool m_alwaysOnTop;
+    QString m_primaryTimeZoneId;
+    QString m_secondaryTimeZoneId;
 
     // Helper methods
     bool isInResizeArea(const QPoint &pos) const;
diff --git a/config.xml b/config.xml
index 06e7a33..b58996c 100644
--- a/config.xml
+++ b/config.xml
@@ -1,9 +1,11 @@
 <?xml version="1.0" encoding="UTF-8"?>
 <ClouckConfig>
-    <FontColor>#ffffffff</FontColor>
-    <BackgroundColor>#96000000</BackgroundColor>
+    <FontColor>#ff00ff00</FontColor>
+    <BackgroundColor>#00000000</BackgroundColor>
     <FontSize>24</FontSize>
     <AlwaysOnTop>true</AlwaysOnTop>
     <WindowPosition>1236,784</WindowPosition>
-    <WindowSize>137,59</WindowSize>
+    <WindowSize>240,160</WindowSize>
+    <PrimaryTimeZone>Europe/Bucharest</PrimaryTimeZone>
+    <SecondaryTimeZone>America/Los_Angeles</SecondaryTimeZone>
 </ClouckConfig>
diff --git a/config_manager.cpp b/config_manager.cpp
index d21086d..6ccf54f 100644
--- a/config_manager.cpp
+++ b/config_manager.cpp
@@ -1,6 +1,10 @@
 #include "config_manager.h"
+#include <QDir>
 #include <QFile>
+#include <QFileInfo>
 #include <QDebug>
+#include <QStandardPaths>
+#include <QTimeZone>
 
 ConfigManager::ConfigManager(QObject *parent)
     : QObject(parent)
@@ -8,9 +12,27 @@ ConfigManager::ConfigManager(QObject *parent)
     setDefaultValues();
 }
 
+QString ConfigManager::defaultSettingsPath()
+{
+    const QString configDirectory = QStandardPaths::writableLocation(QStandardPaths::AppConfigLocation);
+    if (configDirectory.isEmpty())
+    {
+        qWarning() << "No application configuration directory is available";
+        return QString();
+    }
+
+    return QDir(configDirectory).filePath("config.xml");
+}
+
 bool ConfigManager::loadSettings(const QString &filename)
 {
-    QFile file(filename);
+    const QString settingsPath = filename.isEmpty() ? defaultSettingsPath() : filename;
+    if (settingsPath.isEmpty())
+    {
+        return false;
+    }
+
+    QFile file(settingsPath);
     if (!file.exists())
     {
         qDebug() << "Config file does not exist, using defaults";
@@ -77,6 +99,14 @@ bool ConfigManager::loadSettings(const QString &filename)
                 m_windowSize = QSize(width, height);
             }
         }
+        else if (name == "PrimaryTimeZone")
+        {
+            m_primaryTimeZoneId = text;
+        }
+        else if (name == "SecondaryTimeZone")
+        {
+            m_secondaryTimeZoneId = text;
+        }
         else
         {
             reader.skipCurrentElement();
@@ -96,7 +126,20 @@ bool ConfigManager::loadSettings(const QString &filename)
 
 bool ConfigManager::saveSettings(const QString &filename)
 {
-    QFile file(filename);
+    const QString settingsPath = filename.isEmpty() ? defaultSettingsPath() : filename;
+    if (settingsPath.isEmpty())
+    {
+        return false;
+    }
+
+    const QFileInfo fileInfo(settingsPath);
+    if (!QDir().mkpath(fileInfo.absolutePath()))
+    {
+        qDebug() << "Cannot create configuration directory:" << fileInfo.absolutePath();
+        return false;
+    }
+
+    QFile file(settingsPath);
     if (!file.open(QIODevice::WriteOnly | QIODevice::Text))
     {
         qDebug() << "Cannot open config file for writing:" << file.errorString();
@@ -134,6 +177,9 @@ bool ConfigManager::saveSettings(const QString &filename)
                           .arg(m_windowSize.height());
     writer.writeTextElement("WindowSize", sizeStr);
 
+    writer.writeTextElement("PrimaryTimeZone", m_primaryTimeZoneId);
+    writer.writeTextElement("SecondaryTimeZone", m_secondaryTimeZoneId);
+
     // Close root element
     writer.writeEndElement();
 
@@ -150,13 +196,14 @@ void ConfigManager::resetToDefaults()
 
 bool ConfigManager::configExists(const QString &filename) const
 {
-    return QFile::exists(filename);
+    const QString settingsPath = filename.isEmpty() ? defaultSettingsPath() : filename;
+    return !settingsPath.isEmpty() && QFile::exists(settingsPath);
 }
 
 void ConfigManager::setDefaultValues()
 {
-    m_fontColor = QColor(255, 255, 255);      // White
-    m_backgroundColor = QColor(0, 0, 0, 150); // Semi-transparent black
+    m_fontColor = QColor(0, 255, 0);
+    m_backgroundColor = QColor(0, 0, 0, 0);
     m_fontSize = 24;
     m_alwaysOnTop = true;
 
@@ -164,5 +211,7 @@ void ConfigManager::setDefaultValues()
     // Position will be set properly when widget is shown for the first time
     m_windowPosition = QPoint(-1, -1); // Special value indicating "not set yet"
 
-    m_windowSize = QSize(200, 80); // Default clock size
+    m_windowSize = QSize(240, 160); // Default clock size
+    m_primaryTimeZoneId = QString::fromUtf8(QTimeZone::systemTimeZoneId());
+    m_secondaryTimeZoneId = QStringLiteral("America/Los_Angeles");
 }
diff --git a/config_manager.h b/config_manager.h
index c89338d..7e2a654 100644
--- a/config_manager.h
+++ b/config_manager.h
@@ -16,11 +16,13 @@ class ConfigManager : public QObject
 public:
     explicit ConfigManager(QObject *parent = nullptr);
 
+    static QString defaultSettingsPath();
+
     // Load settings from XML file
-    bool loadSettings(const QString &filename = "config.xml");
+    bool loadSettings(const QString &filename = QString());
 
     // Save settings to XML file
-    bool saveSettings(const QString &filename = "config.xml");
+    bool saveSettings(const QString &filename = QString());
 
     // Getters
     QColor fontColor() const { return m_fontColor; }
@@ -29,6 +31,8 @@ public:
     bool alwaysOnTop() const { return m_alwaysOnTop; }
     QPoint windowPosition() const { return m_windowPosition; }
     QSize windowSize() const { return m_windowSize; }
+    QString primaryTimeZoneId() const { return m_primaryTimeZoneId; }
+    QString secondaryTimeZoneId() const { return m_secondaryTimeZoneId; }
 
     // Setters
     void setFontColor(const QColor &color) { m_fontColor = color; }
@@ -37,12 +41,14 @@ public:
     void setAlwaysOnTop(bool onTop) { m_alwaysOnTop = onTop; }
     void setWindowPosition(const QPoint &pos) { m_windowPosition = pos; }
     void setWindowSize(const QSize &size) { m_windowSize = size; }
+    void setPrimaryTimeZoneId(const QString &timeZoneId) { m_primaryTimeZoneId = timeZoneId; }
+    void setSecondaryTimeZoneId(const QString &timeZoneId) { m_secondaryTimeZoneId = timeZoneId; }
 
     // Reset to default values
     void resetToDefaults();
 
     // Check if config file exists
-    bool configExists(const QString &filename = "config.xml") const;
+    bool configExists(const QString &filename = QString()) const;
 
 private:
     // Default values
@@ -55,6 +61,8 @@ private:
     bool m_alwaysOnTop;
     QPoint m_windowPosition;
     QSize m_windowSize;
+    QString m_primaryTimeZoneId;
+    QString m_secondaryTimeZoneId;
 };
 
 #endif // CONFIG_MANAGER_H
diff --git a/main.cpp b/main.cpp
index 9ab8e54..70c8175 100644
--- a/main.cpp
+++ b/main.cpp
@@ -1,6 +1,45 @@
 #include <QApplication>
+#include <QAction>
+#include <QMenu>
+#include <QPainter>
+#include <QStyleHints>
+#include <QSystemTrayIcon>
+#include "autostart_manager.h"
 #include "clock_widget.h"
 
+namespace
+{
+// Standard macOS menu bar icon extent (points). Matches surrounding icons.
+constexpr int trayIconExtent = 16;
+
+QIcon createTrayIcon(const QColor &color)
+{
+    QPixmap pixmap(trayIconExtent, trayIconExtent);
+    pixmap.setDevicePixelRatio(qApp->devicePixelRatio());
+    pixmap.fill(Qt::transparent);
+
+    QPainter painter(&pixmap);
+    painter.setRenderHint(QPainter::Antialiasing);
+    painter.setPen(QPen(color, 1.5));
+    painter.drawEllipse(QPointF(8, 8), 5.5, 5.5);
+    painter.drawLine(QPointF(8, 4.5), QPointF(8, 8));
+    painter.drawLine(QPointF(8, 8), QPointF(10.5, 9.5));
+
+    QIcon icon(pixmap);
+#ifdef Q_OS_MAC
+    // Template image: the system tints it black/white to match the
+    // active appearance, like native menu bar icons.
+    icon.setIsMask(true);
+#endif
+    return icon;
+}
+
+QColor trayIconColorForScheme(Qt::ColorScheme scheme)
+{
+    return scheme == Qt::ColorScheme::Dark ? QColor(Qt::white) : QColor(Qt::black);
+}
+}
+
 int main(int argc, char *argv[])
 {
     QApplication app(argc, argv);
@@ -12,5 +51,46 @@ int main(int argc, char *argv[])
     ClockWidget clock;
     clock.show();
 
+    AutoStartManager::enableForCurrentApplication();
+
+    const QStyleHints *styleHints = app.styleHints();
+    QSystemTrayIcon trayIcon(createTrayIcon(trayIconColorForScheme(styleHints->colorScheme())), &app);
+    trayIcon.setToolTip("Clouck");
+
+    QObject::connect(styleHints, &QStyleHints::colorSchemeChanged, &trayIcon,
+                     [&trayIcon](Qt::ColorScheme scheme) {
+                         trayIcon.setIcon(createTrayIcon(trayIconColorForScheme(scheme)));
+                     });
+
+    QMenu trayMenu;
+    QAction *toggleClockAction = trayMenu.addAction("Turn Clock Off");
+    QAction *quitAction = trayMenu.addAction("Quit");
+
+    const auto toggleClock = [&clock, toggleClockAction]() {
+        if (clock.isVisible())
+        {
+            clock.hide();
+            toggleClockAction->setText("Turn Clock On");
+            return;
+        }
+
+        clock.show();
+        clock.raise();
+        toggleClockAction->setText("Turn Clock Off");
+    };
+
+    QObject::connect(toggleClockAction, &QAction::triggered, &app, toggleClock);
+    QObject::connect(quitAction, &QAction::triggered, &app, &QApplication::quit);
+    QObject::connect(&trayIcon, &QSystemTrayIcon::activated, &app,
+                     [toggleClock](QSystemTrayIcon::ActivationReason reason) {
+                         if (reason == QSystemTrayIcon::Trigger)
+                         {
+                             toggleClock();
+                         }
+                     });
+
+    trayIcon.setContextMenu(&trayMenu);
+    trayIcon.show();
+
     return app.exec();
 }
diff --git a/tests/autostart_manager_test.cpp b/tests/autostart_manager_test.cpp
new file mode 100644
index 0000000..55eda3f
--- /dev/null
+++ b/tests/autostart_manager_test.cpp
@@ -0,0 +1,26 @@
+#include "autostart_manager.h"
+
+#include <QtTest>
+
+class AutoStartManagerTest : public QObject
+{
+    Q_OBJECT
+
+private slots:
+    void createsRunAtLoadLaunchAgent();
+};
+
+void AutoStartManagerTest::createsRunAtLoadLaunchAgent()
+{
+    const QString executablePath = "/Applications/Clouck.app/Contents/MacOS/Clouck";
+    const QString contents = AutoStartManager::launchAgentContents(executablePath);
+
+    QVERIFY(contents.contains("<key>ProgramArguments</key>"));
+    QVERIFY(contents.contains(executablePath));
+    QVERIFY(contents.contains("<key>RunAtLoad</key>"));
+    QVERIFY(contents.contains("<true/>"));
+}
+
+QTEST_APPLESS_MAIN(AutoStartManagerTest)
+
+#include "autostart_manager_test.moc"
diff --git a/tests/config_manager_test.cpp b/tests/config_manager_test.cpp
new file mode 100644
index 0000000..fec1b99
--- /dev/null
+++ b/tests/config_manager_test.cpp
@@ -0,0 +1,40 @@
+#include "config_manager.h"
+
+#include <QDir>
+#include <QTemporaryDir>
+#include <QtTest>
+
+class ConfigManagerTest : public QObject
+{
+    Q_OBJECT
+
+private slots:
+    void roundTripsBothClockTimeZones();
+    void usesAnAbsoluteDefaultSettingsPath();
+};
+
+void ConfigManagerTest::roundTripsBothClockTimeZones()
+{
+    QTemporaryDir directory;
+    QVERIFY(directory.isValid());
+
+    const QString filename = directory.filePath("config.xml");
+    ConfigManager writer;
+    writer.setPrimaryTimeZoneId("Europe/Bucharest");
+    writer.setSecondaryTimeZoneId("America/Los_Angeles");
+    QVERIFY(writer.saveSettings(filename));
+
+    ConfigManager reader;
+    QVERIFY(reader.loadSettings(filename));
+    QCOMPARE(reader.primaryTimeZoneId(), QString("Europe/Bucharest"));
+    QCOMPARE(reader.secondaryTimeZoneId(), QString("America/Los_Angeles"));
+}
+
+void ConfigManagerTest::usesAnAbsoluteDefaultSettingsPath()
+{
+    QVERIFY(QDir::isAbsolutePath(ConfigManager::defaultSettingsPath()));
+}
+
+QTEST_APPLESS_MAIN(ConfigManagerTest)
+
+#include "config_manager_test.moc"