We have just recently released a cool new app TrainBrain:
★★★ Introducing TrainBrain – A multilingual smart application intended for the learning and fast retention of foreign language words ★★★
Link to free version: https://play.google.com/store/apps/deta ... yWordsFree
Link to full version: https://play.google.com/store/apps/deta ... yWordsFull
Available for Android
I recommend you to download this free and awesome app.