diff --git a/gui/src/channel.hpp b/gui/src/channel.hpp
new file mode 100644
index 0000000..acd953c
--- /dev/null
+++ b/gui/src/channel.hpp
@@ -0,0 +1,52 @@
+#ifndef FEDIPOTATO_GUI_CHANNEL_HPP
+#define FEDIPOTATO_GUI_CHANNEL_HPP
+
+#include <QStandardItem>
+#include <QString>
+#include <qstandarditemmodel.h>
+
+namespace FediPotato
+{
+
+    //! Identifier for ChannelItem.
+    enum class id_channel
+    {
+        none,
+        tl_home,
+        tl_instance,
+        tl_federated,
+        conversations,
+        hashtag,
+        filter
+    };
+
+//! An Item for use with #treeview_channel.
+class ChannelItem : public QStandardItem
+{
+public:
+    ChannelItem(const QString &text, id_channel identifier)
+        : _identifier{identifier}
+    {
+        setText(text);
+    }
+
+public:
+    [[nodiscard]]
+    id_channel identifier() const
+    {
+        return _identifier;
+    }
+
+    [[nodiscard]]
+    int type() const override
+    {
+        return QStandardItem::UserType;
+    }
+
+private:
+    const id_channel _identifier;
+};
+
+} // namespace FediPotato
+
+#endif  // FEDIPOTATO_GUI_CHANNEL_HPP
diff --git a/gui/src/window_main.cpp b/gui/src/window_main.cpp
index 2cc766a..a2d76ae 100644
--- a/gui/src/window_main.cpp
+++ b/gui/src/window_main.cpp
@@ -15,23 +15,63 @@
  */
 
 #include "window_main.hpp"
+#include "channel.hpp"
 #include "dialog_about.hpp"
 
 #include <QDesktopServices>
 #include <QUrl>
+#include <QStandardItem>
+#include <QFont>
+#include <QDebug>
 
 namespace FediPotato
 {
 
 WindowMain::WindowMain(QMainWindow *parent)
     : QMainWindow(parent)
+    , _model_channel(new QStandardItemModel(this))
 {
     setupUi(this);
+
+    add_account();
+}
+
+void WindowMain::add_account()
+{
+    QStandardItem *item_root{_model_channel->invisibleRootItem()};
+    auto *item_account{new ChannelItem("@user@example.com", id_channel::none)};
+    item_root->appendRow(item_account);
+
+    // NOLINTNEXTLINE(cppcoreguidelines-owning-memory)
+    item_account->appendRow(new ChannelItem("Home Timeline",
+                                            id_channel::tl_home));
+    // NOLINTNEXTLINE(cppcoreguidelines-owning-memory)
+    item_account->appendRow(new ChannelItem("Instance Timeline",
+                                            id_channel::tl_instance));
+    // NOLINTNEXTLINE(cppcoreguidelines-owning-memory)
+    item_account->appendRow(new ChannelItem("Federated Timeline",
+                                            id_channel::tl_federated));
+    // NOLINTNEXTLINE(cppcoreguidelines-owning-memory)
+    item_account->appendRow(new ChannelItem("Conversations",
+                                            id_channel::conversations));
+    // NOLINTNEXTLINE(cppcoreguidelines-owning-memory)
+    item_account->appendRow(new ChannelItem("#tea",
+                                            id_channel::hashtag));
+    // NOLINTNEXTLINE(cppcoreguidelines-owning-memory)
+    item_account->appendRow(new ChannelItem("#FediPotato",
+                                            id_channel::hashtag));
+
+    treeview_channel->setModel(_model_channel);
+    treeview_channel->expandAll();
+
+    QFont font_channel{treeview_channel->font()};
+    font_channel.setPointSize(font_channel.pointSize() + 2);
+    treeview_channel->setFont(font_channel);
 }
 
 void WindowMain::show_about()
 {
-    auto *dlg = new DialogAbout(); // NOLINT(cppcoreguidelines-owning-memory)
+    auto *dlg{new DialogAbout()}; // NOLINT(cppcoreguidelines-owning-memory)
     dlg->show();
 }
 
@@ -40,5 +80,48 @@ void WindowMain::open_website()
     QDesktopServices::openUrl(QUrl("http://fedipotato.org/"));
 }
 
+void WindowMain::clicked_channel(const QModelIndex &index)
+{
+    auto item{dynamic_cast<ChannelItem*>(_model_channel->itemFromIndex(index))};
+
+    switch (item->identifier())
+    {
+    case id_channel::none:
+    {
+        qDebug() << "None.";
+        break;
+    }
+    case id_channel::tl_home:
+    {
+        qDebug() << "Home TL.";
+        break;
+    }
+    case id_channel::tl_instance:
+    {
+        qDebug() << "Instance TL.";
+        break;
+    }
+    case id_channel::tl_federated:
+    {
+        qDebug() << "Federated TL.";
+        break;
+    }
+    case id_channel::conversations:
+    {
+        qDebug() << "Conversations.";
+        break;
+    }
+    case id_channel::hashtag:
+    {
+        qDebug() << "Hashtag.";
+        break;
+    }
+    case id_channel::filter:
+    {
+        qDebug() << "Filter.";
+        break;
+    }
+    }
+}
 
 } // namespace FediPotato
diff --git a/gui/src/window_main.hpp b/gui/src/window_main.hpp
index 20f0056..dcb2d25 100644
--- a/gui/src/window_main.hpp
+++ b/gui/src/window_main.hpp
@@ -2,9 +2,13 @@
 #define FEDIPOTATO_GUI_WINDOW_MAIN_HPP
 
 #include "../ui/ui_window_main.h"
+#include "channel.hpp"
 
 #include <QMainWindow>
 #include <QLabel>
+#include <QStandardItemModel>
+#include <QModelIndex>
+#include <QString>
 
 namespace FediPotato
 {
@@ -32,11 +36,16 @@ public:
     //! Move assignment operator
     WindowMain& operator=(WindowMain &&other) noexcept = delete;
 
-public:
+private:
+    QStandardItemModel *_model_channel;
+
+private:
+    void add_account();
 
 private slots:
     static void show_about();
     static void open_website();
+    void clicked_channel(const QModelIndex &index);
 };
 
 } // namespace FediPotato
diff --git a/gui/ui/window_main.ui b/gui/ui/window_main.ui
index 811179c..cea5535 100644
--- a/gui/ui/window_main.ui
+++ b/gui/ui/window_main.ui
@@ -13,7 +13,40 @@
   <property name="windowTitle">
    <string>FediPotato</string>
   </property>
-  <widget class="QWidget" name="centralwidget"/>
+  <widget class="QWidget" name="centralWidget">
+   <layout class="QHBoxLayout" name="vbox_main">
+    <item>
+     <layout class="QHBoxLayout" name="hbox_trees">
+      <item>
+       <widget class="QTreeView" name="treeview_channel">
+        <property name="sizePolicy">
+         <sizepolicy hsizetype="Minimum" vsizetype="Expanding">
+          <horstretch>0</horstretch>
+          <verstretch>0</verstretch>
+         </sizepolicy>
+        </property>
+        <property name="editTriggers">
+         <set>QAbstractItemView::NoEditTriggers</set>
+        </property>
+        <property name="textElideMode">
+         <enum>Qt::ElideNone</enum>
+        </property>
+        <property name="headerHidden">
+         <bool>true</bool>
+        </property>
+       </widget>
+      </item>
+      <item>
+       <widget class="QTreeView" name="treeview_posts">
+        <property name="editTriggers">
+         <set>QAbstractItemView::NoEditTriggers</set>
+        </property>
+       </widget>
+      </item>
+     </layout>
+    </item>
+   </layout>
+  </widget>
   <widget class="QMenuBar" name="menubar">
    <property name="geometry">
     <rect>
@@ -27,6 +60,7 @@
     <property name="title">
      <string>&amp;FediPotato</string>
     </property>
+    <addaction name="action_account_add"/>
     <addaction name="action_quit"/>
    </widget>
    <widget class="QMenu" name="menuHelp">
@@ -58,6 +92,11 @@
     <string>About FediPotato</string>
    </property>
   </action>
+  <action name="action_account_add">
+   <property name="text">
+    <string>Add account</string>
+   </property>
+  </action>
  </widget>
  <resources/>
  <connections>
@@ -109,9 +148,26 @@
     </hint>
    </hints>
   </connection>
+  <connection>
+   <sender>treeview_channel</sender>
+   <signal>clicked(QModelIndex)</signal>
+   <receiver>WindowMain</receiver>
+   <slot>clicked_channel(QModelIndex)</slot>
+   <hints>
+    <hint type="sourcelabel">
+     <x>137</x>
+     <y>300</y>
+    </hint>
+    <hint type="destinationlabel">
+     <x>399</x>
+     <y>299</y>
+    </hint>
+   </hints>
+  </connection>
  </connections>
  <slots>
   <slot>show_about()</slot>
   <slot>open_website()</slot>
+  <slot>clicked_channel(QModelIndex)</slot>
  </slots>
 </ui>