I had a look when I did L1 and downloaded a bunch light versions of different apps.
The only one I ended up using and spent $100 on was the Allen Prep Test Bank.
What I liked about it was that I could test myself anywhere where I had 5 minutes but didn’t have my books with me (i.e. the bathroom, on the tram on the way to a night out, in the lift, waiting for a dentist appointment, etc).
What I didn’t like about it was that the content didn’t seem to be up to date especially with respect to FRA. Another thing I would have liked to see was a toggle to specify if I had a calculator with me or not. Any question that required a calculator I would always have to just guess and move on to the next question without really having learnt anything.
Would I buy it again though, no probably not. I used it but in the end it just wasn’t worth the money. It’s easy to get caught up in the “throw money at this exam and I’ll pass it” (i.e get the notes, the videos, the quick sheet, the flash cards, the Secret Sauce, the Iphone App, the CFA hat, the CDs/MP3s to listen to in the car, the meditation music specially designed for CFA L1, etc, etc). But at the end of the day, there is only so much of that that you are actually going to have to use.