build a social app

Hi, we need an app programmer to develop an app similar to lapayh app but different in some functions. The app should allow registration first with mobile and otp code. It allows the client to choose the type of specialty he wants and post his question. 2. the question will be posted to all the registered specialists thru their app accounts. 3. the correct specialist will reply with OK to replay to the questioner. Other specialists will know that the question is taken. 4. client will be directed to payment and then to chat session.
This is a concise circle of the app expected. More detailed picture will be given to the right freelancer.
- text chat + audio notes
-payment method
-both app store and google play
-save chat sessions and audio