Hello to you! Sounds like quite a typical mobile app (no offence), so any well-established IT company whose domain is mobile development will manage. As for the choice of the company, I agree, it can be a tough one as there are plenty of companies today. So my main advice would be to study the company's portfolio, maybe there'll be a case similar to yours. I'd also try to contact their clients for references, as there may be difficulties with the...