A free app for Android, by JR Innovation AB.
Pro Guitar Tuner is a free Android app for guitar tuning. Its developers have been working with professional musicians and guitar makers for many years to create the most accurate and useful app for musicians and guitarists.
It is optimized for Android and has a more user-friendly interface.
This Android app will allow you to tune your guitar with high accuracy and ease. They have added a new tuning mode that can be used with any type of stringed instrument.
It also includes a new library with many high-quality samples of different types of stringed instruments.