Dear Manager,
Thank you for your job posting.
I am interested in what you need, would like to discuss further details via Skype call or chatting.
I am confident with iOS Android app developing including backend + webservice building.
Please feel free to contact me any time.
After you hire me, I will start working immediately, will work my full time to finish your project as soon as possible.
Looking forward to hearing from you soon.
Best regards