It’s a shame this app with excellent content is almost unusable. The app’s buttons (back button etc) when in a lesson frequently become unresponsive . The video control buttons disappear randomly. And there is no way to play the videos in landscape mode, which is basic stuff! I am using iPhone 6 with latest iOS. All in all the app quality does grave injustice to the awesome content. At the minimum, the unresponsive buttons, disappearing video controls (pause, forward/rewind, no skip back 10 seconds!) and lack of landscape mode video must be fixed on priority. Eventually the app must rewritten by some quality/experienced app developers and experts in mobile app user interface/experience . The great content in the app deserves better software for presenting it! Had it not been for the awesome content, I would have given it 1 star.
I have heard how giving you are in so many respects of music schooling and I must say that I am impressed. You remind me of the pure idealism that we had in starting Apple. If I were young, with time, I'd likely offer to join and help you in your endeavours. Keep making people happy, not just in their own learning, but in the example you set for them.
As a beginner, it is best to avoid making a pawn shop, flea market, or yard sale purchase unless you are shopping with somebody who has experience in purchasing a guitar. Having never purchased a guitar, you may not know what to look for in terms of damage or guitar quality. With that being said, a local music retail shop is your best bet. You may also shop online with a reputable company, although be sure to review the business’ return policy.