Get lots of free samples/patchs for iOS apps or as Wav files from Electronicsounds (Donations possible).
Blog Archives
Caustic 3
Caustic 3 is a music creation tool inspired by rack-mount synthesizers / samplers rigs. Everything is real-time and optimized for mobile devices.
But the desktop version is free (No support)
Free iPad Sequencer (Skram)
Click pic to get to Skram @ Itunes Store.