Tetra Sound Editor 4+

Works ok, kinda buggy and way overpriced. Just get lemur and make your own editor.

This is the best iPad editor for the Tetra so far, but it's not entirely working yet. Three problems: (1) It doesn't remember the program banks that were uploaded in the previous session--if one shuts down the app and opens it again at a later date, one has to reload all four program banks. It would be far better if the Tetra editor could remember the last state it was in. (2) There's a big problem with Combo bank functionality--it simply doesn't work. When I tried to upload Tetra's Combo bank to the editor, the Combo patch names never populated the bank list. If one changes the Combo on the Tetra itself, the Tetra editor reflects the change, including the correct Combo name, but the selected Combo names never appear in the Tetra editor's Combo Bank. (3) The row of tiny little buttons at the top of the editor are too small and finicky to function consistently. Sometimes they work and sometimes they don't. Bottom line: Once Soundtower has ironed out these problems, this will be a must buy for all Tetra owners.

For those of you nervous about spending cash on another potentially buggy Tetra editor, I made the leap and am happy to report that all seems to be going smoothly. Using an Apple camera-connection-kit, the iPad connects to the Tetra's USB port allowing a midi keyboard to simultaneously connect via the traditional midi ports.
This editor is very thoughtfully laid out. The individual modules enlarge when touched, making editing the Tetra's complex modulation sources/destinations easier. I'm glad there is finally an intuitive and elegant window into the brain of the Tetra.