SSSSYNTH is free software synthesizer for the iPhone and iPad.

Features:

• OSC x 2
• MODURATION
• RING MODURATION
• OSC SYNC
• GLIDE
• FILTER x 1
• EG x 2(AMP,FILTER)
• LFO x 2
• FX
• DELAY
• OVER DRIVE
• KEYBOARD(SCALE) x 35

The features are limited & MIDI is missing in action, but the price is right.

It’s available now as a free download from the App Store.