As an aspiring guitar player myself, I'll take any help I can get at trying to improve my strumming and picking.
iPlayMusic is a user friendly guitar learning pack which aims to help even the most novice player come up to speed. However, note that this particular download is not actual learning software. It merely gives you access to pick and choose from the hundreds of tutorial videos and packs available from the iPlayMusic Download Store or updates any iPlayMusic packages you may have already installed.
Therefore, this software simply works as a standalone product that acts as a gateway to the rest of the developers products although there are a few free video tutorials and samples available from the Download Store. Everything else will cost you anything between .99 cents and $35. The basic tutorials are just that - unless you're a complete beginner, you won't want to learn too much about the mechanics of a guitar or how to play a G chord. However, the videos on sale look like truly comprehensive learning packages some with over 4 hours of videos complete with GarageBand and Acid projects, pre-encoded iPod videos, and special songs by famous artists not available in the Download Store. All come with split screens showing you the correct hand position, the lyrics and right posture.
If you want a gateway to a huge database of user friendly tutorials and beautifully presented learning videos, then iPlayMusic will have you rocking out in no time.