Looking at this guitar head tuner with the naked eye it looks slightly dull. Up close with a camera and the extensive corrosion can be seen. Amazing that a normal atmosphere indoors can cause so much

GuitarTuna A free guitar tuner app suitable for all levels Screenshots Hunter's comment If you are someone who is only starting playing the guitar, tuning your instrument might seem like a daunting task.

For those who love playing guitar but don't know how to tune this is perfect for you. I do recommend Guitar Tuna. It's free and downloadable from google play. Also, it can tune other instruments such as

Components Guitar Tuner is a very simple open source application, this application is to adjust the sound of strings on the guitar in accordance with the guitar setting in general, guitar key components

This video is a guitar standard tuning guide, so you can play along and match the pitches by ear. Standard tuning on guitar is: E A D G B e - and it's in concert pitch of A440 HZ: