This app is capable and complex FM synthesiser that can create rich and very strange sounds combining up to 10 sound generators. Every generator can be adjusted up or down from the main frequency almost without restrictions in range. There are 4 possible wave forms for the generator output and you can tweet the volume, modulation and add some tremolo effect. You can listen to the result sound while you are adjusting the new generator and just add it to the result when it sounds good.
With the Sound Maker Synth you can also add reverb and then play it as a one voice synth using the one octave keyboard at the top. The app is very capable to create some strange and alien like pad sounds as some dubstep bass.