In the above video, I have talked about 10+ Mobile App Development Companies in the United States & United Kingdom.
They are as follows:
1. Messapps
2. VironIT
3. Shakuro
4. Fueled
5. Intellectsoft
6. Y Media Labs
7. ScienceSoft
8. Atomic Object
9. Exadel
10. Zco
11. 360 Degree Technosoft
12. Blue Label Labs
13. Eleks
14. Nomtek
15. IIH Global
16. Blueberry Consultants
17. Apptunix

Click on the link to know more:
https://www.softwarefirms.co/blog/top-mobile-app-development-companies-in-uk-and-usa-for-higher-roi