Apps

The main menu (the side scrollbar, Design interchangeable): 

images, 
Music, 
Movies, 
file 
Internet browser (mouse recommended) 
settings 
Apps 
TV-Fee (TV with ad blocker, DVB-S) 

Each submenu is again a standalone app, also other apps are preinstalled: 
TV Pilot (Top TV of the day), 
Calendar, 
clock, 
Download Manager, 
E-mail client, 
Google Search, 
System Upgrade, 
Standby Manager, 
App Installer (for local apk files) 
Play Store (for apps from the Google Market install) 
Set-up Assistant (setting at the beginning), 
DTV (Replacement TV app) 
u.v.m. see www.fernsehfee.de/apps 

It can be installed any number of apps (programs) and games. 
Good apps are self-explanatory, so only the one tip: 

Delete apps: Settings> Apps-> Select App> Uninstall 
or even easier if apps are via App AppInstaller locally on the stick: 
there click on the yellow star (yellow = installed, click = uninstall, gray = not installed, click = install)