Measure acceleration from any orientation

G-Force uses the 3-axis accelerometer to analyze vehicle performance. Measuring performance with the accelerometer is more accurate and reliable than using GPS.

G-Force uses real-time 3-D rotations and auto-senses the direction of gravity so performance can be measured with the device in any orientation.

This app is free, has no ads, and lets you test how well it works on your device. The full version measures straight line acceleration performance, saves results in files, with plans for more features based on user feedback. It is here:

https://play.google.com/store/apps/details?id=com.mrc.gforce

Details:

http://mclements.net/clementslogic/gForce.html