Hi,
I have 4+ yrs of experienced as an android developer and i can do this task for you. I have few question regarding your requirement,
1) Are you looking for native android application/cross platform?
2) As you mention that you want to identify that user action are actual not from robot or other applications, do you have user authentication? if we have user login then we can easily put security check in web api calling.
3) Could you please explain in detail about "integration of mobile app with web site"?
I am new to this site but i promise you that if you give me chance then i will give you best possible solution, as well as i will give you support for long time. If you could share me your skype details then we can have discussion about above mention points.
Please let me know if you have any query or concern.
Best Regards,
PyDroid Dev