Soko++ for Android supports Solver plug-ins. Here you can find an example plug-in.
This example app contains all solutions to Soko++'s built in levels. The solutions are simply read from a resource file.
Soko++ calls the plug-ins with a specially defined intent action; nl.joriswit.sokosolver.SOLVE. This intent gets one extra string parameter called LEVEL. This is the level in XSB format. When you find a solution, set RESULT_OK as the activity result, and add a extra parameter called SOLUTION, with the UDLR string.
This plug-in is also available on Google Play