Happy New Year 2018!
According to my understanding and analysis, you required a Mobile App (iPhone & Android) like instagram with exceptional feature of only you and 3 other admins have rights to post content. However, Instagram type App cannot be done in US $1,500, as this is very unrealistic budget, because there are lot of features in Instagram App.
I believe, you want following 4 projects:
1- Native iOS App (Like Instagram with additional features)
2- Native iOS App(Like Instagram with additional features)
3- Admin and API WebServices
Please ignore the bid amount, as our estimate is high & I would like to discuss.
Look forward to hearing from you & start further discussion thru' private chat.
Regards,
YK
LEADconcept