using a bonita workflow in an android application ! how can i do it ! help please
You use REST!
here are some thoughts:
https://spring.io/guides/gs/consuming-rest-android/
https://developers.google.com/drive/v3/web/quickstart/android
http://stackoverflow.com/questions/8267928/android-rest-client-sample
And if you are really adventurous try Microsoft’s new development
programming for the mobile platform with no coding! (???) 
Google search is an amazing thing…
regards
Seán
PS: If this reply answers your question, please mark a resolved