Spring is made on top of JAVA, and Java si for backend development so you won’t be able to make a mobile application using Spring only; it will hold the datas management, the critical logic but will never handle mobile application UI.
Nevertheless, you made me curious and i search for a Spring integration with Android; as Android being made on top of Java and used to build Android applications it could exist, and it does: Spring for Android, but you’ll still need to learn Android.
As a full-stack developer i recommend you to make your backend with Spring, and follow these steps:
1. The Service Layer on the web server should be created first. For this, can be used framework named “Spring” or Spring Boot”.
2. The Service Layer having the complete functionalities about REST API’s that’s what it’s suggested to create first.
3. In the next step to build the application, you can choose Native Android or Native iOS, but the better and the best option would be, go for React Native as both users android or iOS can download and use the application.
4. In the fourth step, the application will be starting its communication with the service layer as it has the REST API’s.