Timelapse mode
The first screenshot show how the app works without a Triggertrap dongle attached (presumably, how it should work) showing the number of seconds until the next exposure and the number taken so far.
The next screenshot shows the screen when attached to my Canon 400D, taking pictures but not showing anything useful on the screen.
General
The app sometimes shows the option 'Buy the Dongle' and sometimes not, even with a dongle connected.
To exit the app takes many presses of the Android back button sometimes, when on the main menu. However, this may be a problem with Android/my Sensation XE as it does seem to occur on other apps.