Xmind - Xmind is a brainstorming and mind mapping application.

Tuner Eclipse - A simple and accurate guitar tuner for iOS

MindManager - With MindManager, flexible mind maps promote freeform thinking and quick organization of ideas, so creativity and productivity can live in harmony.

Roadie Tuner - Fine tune your guitar in seconds

MindMeister - Create, share and collaboratively work on mind maps with MindMeister, the leading online mind mapping software. Includes apps for iPhone, iPad and Android.

Guitar-Tuner.org - Guitar Tuner | Online Tuning | Guitar-Tuner.org