I finally figured they do not work in the app. That is bad.
However, what is worse is the fact that whole of the documentation about custom powerups never states this anywhere. Only at the end of developing a powerup, one realizes that it won't work on Android.
One of the threads on the forum suggests using Trello in mobile browser as a workaround but that is not usable at all. It's design is unprofessional and I can't share it with my customers. Top 40% of the screen is being consumed by fixed buttons.
I had shared these concerns on relevant threads but did not get any response. So sharing again.
Is there any plan for supporting custom powerups on Android or fixing Trello mobile browser UI?