Measures 2 is a handy application with a Protractor, Ruler, Spirit Level, Surface Level, Seismometer, Flashlight, and more tools.
https://mega.nz/#!7QNCVYTK!Q0-j6mSVE7xfqwIe1tNBDD13d9jzfMqrKpAyxS0vSo8
https://mega.nz/#!7QNCVYTK!Q0-j6mSVE7xfqwIe1tNBDD13d9jzfMqrKpAyxS0vSo8