Hello! Thank you very much for the advice, actually, I almost lost hope in getting any reply. I'll check the company, thanks again.

Hello! I want to create an app for myself. A cross-platform one. Likely, it will be on Ionic. I want to hire an outsource company not just one developer because it is a great amount of work. The app is designed for counting calories using a non-standard approach. All the data would be registered and synchronized with smart devices (watch, weight, pulse tracker and so on). So what companies should I hire for it? You know any? How can I choose a good...