The process of developing an app for a mobile device, such as a smartphone or tablet, is called "mobile game development." A popular way to do this is to use Unity or Unreal Engine. If you're a developer and don't have the resources to develop games for this platform, you can hire companies that specialize in it and have experience with it.
Developing your own game can be a challenge, especially if you don't have experience. One solution is to use the services of an outsourcing company that specializes in mobile game development. Experienced developers can do all the necessary work on a particular project while you handle other important aspects of your business.