My Android app has an Undo button in the action bar:
Many users are confused between this Undo button and Android's hardware Back button (which exits the activity).
Even I sometimes press the wrong one.
Are there ways I can reduce confusion between the two?
I was asked for precisions about my app so here you go: It is a flashcards app where the user presses Again/Hard/OK/Easy after revealing the answer. Many users use the app several hours per day, at around 2000 flashcards per hour. Mis-touch typically happens a dozen times per day, for instance pressing "Hard instead of "Again", which has very bad consequences, so an Undo feature is needed.