Your backend language is almost entirely irrelevant to a mobile application. You will probably be using a network-based API to communicate between the two, and any backend that can speak your preferred protocol will suffice. These days, JSON over HTTP is a common default choice, and Spring supports it out of the box with literally no configuration required (and makes using OAuth very easy, which is nice for mobile applications), but you could choose any backend you like.
Spring Android is an Android-friendly implementation of a few Spring client features, notably RestTemplate
, and entirely agnostic of the backend it's talking to. These days, Retrofit and Volley seem to be more popular choices for Android, and both will work just fine with a Spring backend.