The experiment “Acceleration (without g)” just gives the raw data from the phone’s (typically virtual) accelerometer.
The experiment “Acceleration with g” just gives the raw data from the phone’s accelerometer.
Explore the relation of angular velocity and centrifugal acceleration using the gyroscope and the accelerometer. (For example when putting your phone into a salad spinner)
Measure the inclination of a plane.
Measure the time between two or more acceleration events. This uses the accelerometer to trigger a stopwatch by (small) mechanic shocks.
Measure the frequency of a pendulum on a spring.