Dear, sir.
Thanks for your invitation.
I have just read your requirement carefully and had very interesting in your project.
I have a lot of experiences in development of mobile application for video App, image App, chat App, messaging, social networking, restaurant reservations ,ADS, Push Notification, Google Map, and so on.
No problem.
Of course, I know you could be in doubt about my real ability.
It would be important for me to prove my ability through real project.
I hope this project would be the first step in long term partnership with you.
If you trust and award this job to me, I can be trusted to do the work well on high quality and schedule time.
You may rest assured that we shall honor our commitment.
I await you favorite reply with interesting.
Best regards.
Chai.