Dear, sir!
I've checked your job description carefully. I 'm very clear what you want to do and thus i can finish your app with high quality within your deadline.
But before i start your work, i'd like to ask a few questions to confirm your requirements more in detail. And i have some idea to make your app more attractive.
So i'm ready to discuss those questions and ready to start your work immediately .
Waiting for your answer.
Thanks