It comes with unlimited tracks and four effects plus five instruments and most importantly a save function in the free version. Of course it is to trick you into a upgrade but it's all good as the free features are definitively good enough to make some serious music and to test the application properly.
There is a Android version and a Windows version.
To visit their website:
http://us.openlabs.com/
Here is the update information:
Stagelight is now FREE with
-Unlimited LoopBuilder tracks
-4 included effects
-5 instruments (with unlockable extras)
-Saving and Sharing your music
**All other features are unlockable via in-app purchase**
Phablet/Phone Support Added
-New Vector graphics for better scaling.
-New Universal Inspector design
-Consolidated Tool bars
-Much more
-MIDI device support (Android 6.0+)
-Audio Device Buffer Size Control
-Bug Fixes and CPU Optimizations
-Fixed text input using Samsung and Asus keyboards