Mobile App Frontend is what your users will see. Mobile frontend development includes a mixed bag of technologies. Some applications require APIs and backends, while others only need to work only with local databases offered by the platform.
Almost all web programming languages can be used to build the backend of your mobile application. If you are building native applications, you can use technology specific offerings. For example, iOS applications can be developed using Objective-C, Swift Programming Language, Flutter, or React Native. Android Applications can be developed using Java, Kotlin, Flutter, or React Native.
Every programming language offers its own unique capabilities with your desired platform. You should be able to choose a team that understands which necessary technologies can be leveraged the most by choosing the perfect programming language.