The existing and official Antwerp Velo app is nice, but it has one big flaw. When you put back your bike, you get a notification if it is put back correctly. However, if there is a registration problem, you don't get any notification. If you only find that out a few days later, you'll get a €150 fine.

I therefore decided to reverse engineer the Antwerp Velo API and create an app that shows you a Live Notification while you're riding the bike, so when you look at your phone after getting off the bike, and you see the timer is still running, you know your bike wasn't registered correctly.