Agile Partners, best known for creating an exceptionally useful $9.99 iPhone application called Guitar Toolkit that packs in a guitar tuner, a metronome, and fantastically detailed chord and scale charts, on Monday released its first follow-up app.
Tab Toolkit won't have as large an audience as Guitar Toolkit, which is immediately useful to players of all levels, as it assumes that you have (or can get) tab charts--and that you know how to read them. But if you're a serious guitarist, $9.99 is a fair deal for a very sophisticated app that performs well--no freezes or stutters, as I've experienced with some other music-oriented apps. (If you're just learning about tablature, the $2.99 iPractice is probably a better first download.)
So where do you get tab files? If you're a songwriter, you can use Power Tab Editor (freeware, Windows-only) or Guitar Pro ($59, for Macs and Windows PCs) to create your own. There are also online libraries of tab files for popular songs and artists--GProTab has a particularly extensive collection of Guitar Pro files--though copyright holders periodically crack down on these sites, which generally operate outside their approval.
Once you have some tab files on your computer, Tab Toolkit lets you transfer them to your iPhone directly over your home wireless network. It also includes an embedded version of Safari so you can download tabs directly from the Web. Tab Toolkit does support PDF and rich-text tabs, but you get the most results if you use PowerTab or Guitar Pro files.
At last, once you have some PowerTab or Guitar Pro files on your iPhone, the fun begins. Tab Toolkit scrolls through the song at the correct tempo, displaying both traditional and tab notation, with a metronome and synthesized version of the instrument to keep you on target. It fully supports multitrack tabs for the same song--for example, I was able to download all three guitar parts, bass, and drums for Metallica's "Master of Puppets," and follow through each individually--and you can stop the automated playback and scroll through the chart manually to learn particularly tricky parts like Kirk Hammett's guitar solo. You can display either a guitar fretboard or piano keyboard on the screen to help you with fingering, and can even flip the guitar upside-down if you're a lefty.