Pinion angle and drivetrain vibration

The app is works with the engine and transmission in the car and all the weight has to be on all 4 wheels. You just need flat surfaces like the bottom of the oil pan or the back of the engine. With this app it should only take you 5 mins to find out were your problem is but if the engine and transmission are both angled up and the pinion is up you will not need an app for that most of the time I set the engine and transmission down about 1 degree and on an automatic the pinion is down about 2 degrees and with a stick down 4-6 on a leaf spring car so on acceleration the pinion moves up so the driveshaft is just about straight. That seems to work most of the time if you have ladder bars you can set it were you want it because there is no pinion angle change on acceration but you never want the pinion up it puts the u-joints at an extreme angle which will lead to driveshaft failure.