@Sinely It's crucial to choose a company that helps us to bring the best outcome through their development approach.
I am in the app development industry for 5+ years and I know the major headache is partnering or finding the perfect professional to work with.
I do have some suggestions for you that might be helpful to you.
When we search for an app development company, the first thing we need to understand our objective and what kind of app we wanted to create with the help of the development team.
Then we need to research a bit of the best companies information which we can obtain from the clutch, goodfirms, and business24 and there are so many business directories.
2nd step would be going through their portfolio individual to see is the company has built an application previously which has similar features to ours, and if they had then what features they have leveraged in the app and what negative aspects hurting the ux of that application.
Even you can go beyond that by contacting that app founder or support and ask them about the development approach they will help you and if they not then we can look at some other companies, but the blueprint would be the as same as the above.
Along with this, I have some app development companies in my mind that can be a good to start working with for your projects according to my years of experience in the app development sector.
These companies are from the USA only, I don't know about others much.
Fortunesoft IT Innovations - App Developers in USA
bromin7, Inc. - Top-Notch Mobile App Development Company USA
Cerdonis Technologies LLC - Mobile App Development Company in USA
Techugo - App Development Agency in USA
Consagous Technologies - Best Mobile Application Development Services in USA