Hi Sir,
I reviewed your job requirement and excited.
I have rich experience in backend webservice with admin panel development for mobile app.
I have just delivered such a job to client from the Turkey recently, please take a look at this site.
https://www.freelancer.com/projects/PHP-HTML.1/PHP-MVC-mobile-app-expert.6726365.html
https://www.freelancer.com/projects/PHP-HTML.1/PHP-MVC-mobile-app-expert.html
It speaks for itself.
Let's discuss further detail.
Sincerely,
An