SunVox is a great tracker based audio program with built-in FM synth for creating music in Windows and Android environments. Author: Alexander Zolotov. Russia.
+ lightweight and powerful
+ mobile optimized super fast algorithms
+ XM [FastTracker] and MOD [ProTracker, OctaMED] import
+ Midi import/export
+ many other features, check by yourself
+ costs nothing, but you better greet [donationware]
NO CONS FOUND
Also, you might be interested in my Music Tracker Database project. It covers all available music trackers on all platforms. SunVox among them too!