Ideally, something that enables someone to explore chord variations and combinations in a relatively intuitive way, and then be able to record or sequence a progression fluidly on the fly. No computer screens or mouse clicks, just smooth Push 3 UX. Something along the lines of Oxi One's chord mode workflow would be good, obviously adjusted for Push 3's workflow nuances.
Would love something that takes full advantage of Push 3 integration/takeover options. Where's Ian Dicke when you need someone to create an amazing flagship chord tool that takes full advantage of the P3's hardware and does so in a "it just works" way out of the gate?! Maybe someone already had created such a tool, and you're going to provide a link to the holly grail I've been looking for..right...about...now...