A few apps seem to come close, but there are some problems.
If you're typing out your own music, you simply enter the chord name in brackets in front of the word you want it to appear over on the final product. Let us know in the comments below!
Tabs can be created with rows of dashes that represent the guitar strings; they will be formatted a bit more nicely when you're done, and you can add hammer-on and pull-off notes as well.
For me, the process usually involves finding the right transcription of the chords in the correct key online, copying the relevant bits from the web page and then creating a PDF on my computer for upload to Dropbox and my iPad so everyone can access it.
General Scoring Software with Tab functionality These software tools are designed for the general musician to create standard musical notation. Launching the app, you'll see a fairly basic interface without any clutter to get in the way.
Like Coke and Pepsi, Ford and Chevy, Macs and PCs — there are just different groups of people who are strongly committed to either brand. Another is the real music sampling done by folks like Victor Wooten, so you can play back your tab in style.
Overall though great. GuitarPro is an app for tab playback and editing, but the iOS version is pretty limited in terms of creating tabs from scratch.
An upcoming app called TabBank, currently in beta and set to release on July 27th, aims to simplify this process quite a bit, with a simple way to create and import chord sheets and tab right on an iPad or iPhone. This would make creating guitar tabs so much more easy and fun, and with more and more guitarists moving to 7, 8, and 9 string guitars these days, this app would be used by a lot more guitarists.