iAlign 4+

I can't say how well the camber and caster measurements work because the calibration doesn't work right. To calibrate, you get to the calibrate screen, place the flat back of the phone on a known vertical surface (which means you need to calibrate a surface with another level) and press the 'calibrate' button. You are then supposed to move on to measuring the camber.

Two problems. First, if you keep the back flat on your calibrated surface and rotate the phone clockwise and counterclockwise, the camber number changes. This should not happen. If this kind of rotation is going to affect the camber measurement, then some sort of level needs to be added to the screen.

Second, if you keep the phone as vertical as possible, but rotate it about its vertical axis, the numbers change. If you rotate the phone 180 deg, the camber measurement will add over 100 deg. This makes no sense whatsoever. That means my calibrated surface needs to be parallel to my wheel surface. Clearly the accelerometer angle transformation matrices are completely messed up.

The app is a good idea, and with the processing power of a smartphone, one should be able to develop an app that could step you through an automated process with decent repeatability. But this app isn't it.

This tool provide quick measurements very accurate. Very satisfied

This app could be great if it worked. My actual front wheel camber was -2.0 - this app said it was -6.2. No way. My other angle finder app for the iPhone (clinometer) reads correctly, so it CAN be done, hopefully they'll fix it because the caster function is cool if the can get it right. As of now, it is useless.