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
G力采用3轴加速度计来分析车辆的性能。与加速度计测量性能更加精确，也比使用GPS可靠。
G力采用实时三维旋转和自动感测重力的方向，使性能可以与设备在任何方向来测量。
这个应用程序是免费的，没有广告，并且可以测试是否能正常工作的设备上。完整版测量直线加速性能，节省的结果文件，并计划根据用户反馈更多的功能。是这里：
https://play.google.com/store/apps/details?id=com.mrc.gforce
联系方式：
http://mclements.net/clementslogic/gForce.html

Version 1.5, fix for some devices that wouldn't run this app - if it didn't work before, give it another try!
Version 1.4, fix for a rare and obscure crash.
Version 1.3, bug fixes and notice that full version now computes Power output
Version 1.2, fixed some typos (it said it used GPS, but it doesn't).
Version 1.1, added links to the full version.
Version 1.0, built for any device, phone or tablet, Android 2.1 or newer.