A couple of users suggested we should make video tutorial to help people understanding our apps. So I made two simple videos to get this effort started. More videos will be added over the time. I have to confess it is not easy to make a nice video :(

Measure something longer than the phone length using the screen ruler feature (for either Advanced Ruler or Advanced Ruler Pro)

How to manually calibrate the screen ruler (for either Advanced Ruler or Advanced Ruler Pro)