hey folks! I have an idea and I want to create an iOS app (maybe android too but a bit later). Could you recommend what are the main criteria which I should pay attention to when I will be choosing a company?

Development life cycle and cost of prototype for your idea. Prototyping your idea will help you in so many ways so ask them for that first.

Well, its great you have an idea and you want to develop an app for it. You have to go on a search for various app development companies and you need to check their website.From the company website you can gather a lot of information you can even check on what technologies they work on and what benefits you will be getting by working with that company. If you are really looking for development company I would like to suggest you read this article https://steelkiwi.com/blog/tips-how-employ-best-team-developers-your-project/. Hope it will help you

Thank you guys for your help. I will update you after choosing the company

Like someone said above

Development life cycle and cost of prototype for your idea. Prototyping your idea will help you in so many ways so ask them for that first.

That answers it all. Now if You are gonna be thinking of the perfect IDE to use

Learn objective C on mac learn how to use xCode (Development IDE for Mac)
On windows? You can create a Cross platform Application with Visual Studio using Xamarin.