Apart from that you can record videos and attach them to tabs so that you can see your improvement. To learn more about video recording, please read this article: http://support.ultimate-guitar.com/knowledgebase/articles/1158937-how-to-record-video-in-tabs-iphone-app
To start tracking your progress:
1) Press "+" button at the bottom right corner.
2) Press "Start Tracking".
3) When you've finished practicing press "stop" button.
4) If you want to continue practicing, press "Continue Tracking" and if you learned this song press "I Can Play"
5) Your results and statistics will be displayed in "Tab Tracker" section of the app.
Tap on "songs learned" to see which songs you can play or tap on "daily goal" to keep practicing.
Note: Tab Tracker is not included to Pro Version upgrade and it should be purchased separately.