As a developer I know what it's like to program an insanely awesome application and then have people say, "Ok but can it do [extra stuff] too??", so let me preface this by saying, awesome job. I installed the iPad app, works flawlessly, UI is pretty and intuitive, and of course the functionality is huge. Finally I have a way to actually make my iPad productive, instead of playing stupid games...

My feature request (more of a "me too") is the ability to notate in a chart when it is changing key. (as has been requested here) This would allow users to take advantage of the Nashville view in standards that change key for several bars, like Body and Soul, Tune Up, etc. (ie, probably a majority of jazz tunes) I realize that this functionality would have no effect unless people actually did some work on their own to add these modulations to the charts, but I suspect the community would work together to update the tunes (I know I'd update a ton of them myself). In the interests of pleasing everybody, it'd probably be best as an optional thing (ie, keep "Number System" as an option, and add "Number System (modulations)" as a new option). As for how to display the modulations, I'm not particular. On my own charts I use a diamond with a number inside it, relative to the original key; so if a tune modulates up a half-step, it would be a diamond with #1 inside it.

Once again thanks for the great app!