Developer Pablo Lopez has release a new iPad synthesizer - 4Waves Synth AUv3 - described as an easy to use synthesizer with a powerful sound. He says that its characteristics make it perfect for learning about oscillators, envelopes, filters and effects; for live music and in general if you need a powerful sound easily and quickly.
It can be used as standalone and as an AUv3 plug-in.
Pricing and Availability:
$3.99 at the app store.
More information:
With the Boss RC-505 MKII
Super flexible synth from U-He and it's free
If you want a compact sampling workstation
New ambient algorithmic reverberator