App Upgrade.

I had my app developed by a Los Angeles-based IT company, Scrum Launch https://www.scrumlaunch.com/ , who have been providing technical support for several years. The developers of the company can create you a multifunctional application in any programming language at excellent prices and with a guarantee of its performance.

Can you suggest a good app development company? But I don't need to fix the application, I need to create a new one. 

What exactly do you need to develop? Because there are many programmers and everyone has a different attitude to their work, and there are different areas, different specialisations. To create a website, you need to contact the programmers, agree on the language, the deadlines and whether they will be in touch after the work is completed. I can suggest you contact this company in Canada https://innowise-group.com/web-development-services/