Isaac, 3 months will be great to complete this project, as prototypes are already designed along with all the requirements which are very clear as well,
I reviewed your clickable mockups, sitemaps and wireframes
How about if we convert the completed modules in React Native and proceed with this technology? to complete all the other incomplete features,
Actually we have a team of expert React Native developers and we already have worked on the features which you have featured in the attachments,
We can do the tasks on milestone basis,
Regards,
Sam