I have it and it's alright. The tracking mode is very smooth and easier than Jantzen's sim when using a hotas stick, however, you use rudder pedals rather than a throttle. There are no emergency procedures for the tracking mode, it only has you listen for certain numbers/letters and you pull the trigger when you hear the right one. Unfortunately, it's not like the ASTB where you have to differentiate between each ear. Jantzen's sim offers the same exact features as the tbastestprep software when it comes to the tracking mode.
The UAV mode is cool because you have a couple of settings you can alter like the speed and whether to enable ordinal directions.
There are two other modes called Aural Memorization and Multi-Tasking. I think multi-tasking might resemble the emergency procedures but I am not entirely sure since I haven't taken the ASTB yet. Aural memorization just gives you 5 letters to remember and you click when you hear the right letter. Pretty dumb since the tracking mode has the same exact thing.
I think you should just save your money and stick to using Jantzen's sim with a hotas and practice UAV using flashcards and that app you have.