With DataSnap Mobile Connectors it is possible to generate in automated way the DataSnap client classes in different languages like C# or Java for Android for example.
For HTML5 client application a JavaScript proxy class can also be generated from the DataSnap REST Application wizard.
In FireMonkey client application you have advantage it is possible to share units with server project. With the generated proxy classes in other languages it remains to be seen if business logic is also included. It is a good starting point anyway.