Over the past couple of weeks since NAMM, there has been some positive buzz about the new iPad app from Korg called Gadget. I decided to pick it up this past week since it is on sale for ~$28. The price isn't cheap, but the software is really well designed. It is the first iPad app that for me has really found the perfect sweet spot of features and usability on the iPad.
I have tried numerous iPad music creation apps before and the top contenders for me were either Sunvox or Retronyms' Tabletop. Sunvox was great in that it had the full synthesis capabilities that I was looking for, along with the ability to easily bring the music back to the desktop. From a pure synthesis point of view, it is probably the most powerful app on the iPad. The interface however is not optimized for touch, and while Nightradio has done an admirable job and making the interface friendly, there are still some elements that don't full fit well with a touch screen.
On the flip side you have Tabletop, which is all instrument based, which works really well for me since I am very familiar with working in a groovebox sort of environment. The only thing that really held me up in Tabletop is that the song based sequencing is really poor. They have a pattern trigger box, which sort of triggers different patterns on the machines to create a song, but it is clunky and confusing. It is also sort of a pain to have to jump around to each instrument to then select and create the patterns.
Korg's Gadget has seemingly struck the best balance I have found so far. It has a very intuitive piano roll interface with a track for each instrument. Patterns are arranged in an Ableton Live sort of scene mode, where the next group of patterns triggers, sort of like how old school trackers work. The best part though is that there is a solid collection of synthesizers that have some real sound creation capabilities included. It is only v1.0 so far and there are a few UI quirks to be sure, such as the app always starting at the beginning of the song rather than the scene I am working in when editing, but I imagine those will all get worked out over time. It is a really strong showing so far and I am really enjoying my time with the app.