Anki is great. I have been using it to prepare for my exams. Creating flashcards on my laptop and learning with them on my Android phone / tablet works like a charm. Also, the Android app just got updated. The only limitation I've found is that there is currently no way to self-host flashcards which can be accessed by the mobile app. If you're only using the desktop version you might want to look at https://github.com/dsnopek/anki-sync-server in order to self-host your flashcards.