Sensor Spy for Android is an application from Intrepid Control Systems that lets you quickly interface with sensors. These sensors can be inside the mobile device or outside the device. Some sensors you can only monitor and some sensors you can control (officially called actuators but we do not want to be too technical).
Sensor Spy lets you display your sensors in custom panels and make the mobile device respond to sensor changes (called Mobile Actions). You can also record or log your sensor values to files on your SD card.
The main screen is shown in Figure 1.