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

https://web.powerapps.com/

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