A free app for Android, by Bialamusic.

Chromatic Tuner is an application that allows you to tune your guitar, violin, flute, and other stringed instruments to the most accurate level. It works for a wide range of instruments. It is a very fast and precise tool that gives you the most accurate level of tuning.

The application is very easy to use and it has a simple interface. It shows you the exact level of frequency, and it is highly responsive. Another great thing about this chromatic tuner is that it is capable of working in noisy environments. Hence, you can rely on it for precise tuning no matter where you are.