Hello, among the studios that provide services for the production of mobile applications, the following types can be distinguished: freelance professionals, lone professionals, companies that use templates and designers, and companies that are engaged in individual development. Personally, I would recommend that you contact a company for Light IT, which has extensive experience in developing applications for all areas of business.
When you need to create a new mobile application or make an app modernization, you definitely should make a thorough analysis of your potential developers.
Take a list of software development companies and check them by several parameters like expertise, experience in different industries, number of cases, reviews and so on. Then, you can make an initial call with each company representatives to establish a personal contact.