After installation of #!++ are some launcher defined in the tint2 configuration, but not shown.
Open the file tint2rc from the menu by selecting

Settings -> tint2 -> Edit config file

Add a L to the panel_items entry in front of TSC. L is for launchers.

Go to the Launcher section.
There are four launcher_icon_app entries. The both in the middle do not work.
Change them to Thunar.desktop and geany.desktop. Gedit is not installed by default in #!++.
Creating launchers is very easy.

Restart tint2.

The result should be like the picture below.