Fine Tuner - Fine Tuner is a minimalistic guitar tuner that utilizes your device's built-in microphone.
Guitar Dashboard - Open-source interactive music theory for guitarists.
MyGuitarTuner.com - Online microphone tuner for guitar, ukulele, violin and other instruments. Tune by ear or using the microphone of your device. It's fast and accurate algorithm makes it one of the best online microphone tuners available.
UltimateGuitar.com - Learn how to play your favourite songs on guitar or ukulele
Metronomus - Powerful and beautiful online metronome
Tabs Lite - An ad-free open source guitar tablature application using an existing popular tabs database. Built for speed and simplicity.