Dear Sir,
This is a Web App but responsive, means mobile friendly and compatible to all the major mobile devices.
I am not sure if others are really estimating it according to the overall features/functionality, because I know 95% bids would be below US $750, as you have selected this budget. Even if you select US $1,500, then again bids will come below this range :).
Anyway, I have also discussed with one of my senior team lead and he also agreed that this will take 20-25 working days depending on your quick feedback & response time.
Please initiate the chat to finalize the contract details, estimate, payment terms etc. but just so you know, I am flexible in prices, as quality comes first for me and then prices.
Look forward to hearing from you & start further discussion thru' private chat.
Regards,
YK
LEADconcept