Just yesterday I was searching for an Android open source & offline translator, but finding none I have resorted to Google Translator without the network permission.
Today I found this, really cool and it also includes an OCR:
Discussion
Yes 💯 Using it on Graphene, it works great. The only lacking feature is playback voice to hear how to pronounce things but ultimately it's not necessary and forces me to say things rather than play a recording. I'm really grateful it exists after initially not finding anything offline as well.