RideData with Just your phone
You can use RideData with just your phone, it records your speed and location, and will record some data from internal phone sensors. If you enter in an accurate vehicle weight on the settings screen you can also get a horsepower estimate.
To record with just your phone simply open the app and tap + to start a new ride, and tap the checkered flag on the top right corner of the app to start recording. When you want to stop recording tap the cloud icon in the top right corner of the app. You can view your data back after that on maps and graphs, though some of the data will just read 0 where it wasn't recorded.