I'm using the Google Vision Android library for OCR application (according to this) and when I run the application, textRecognizer.isOperational() method returns always false. I think it's because Google Play Services cannot download the required OCR file but it works in some devices. Is it possible to manually download and add the required file?
I myself solved my problem with another free OCR SDK named RTR-SDK which is free and also On-Device. It has a good documentation and separate SDK for IOS developers too.