Sensors play a vital role in the proper functioning of an Android phone. When you pick up a call, the proximity sensor is activated to prevent any touch inputs to the phone during the call. Similarly, a sensor is activated to detect your fingerprint when you try to unlock your phone.

You can do many things with these in-built Android sensors, like checking if your device is working properly or checking the status of the GPS, among other things. So, let's look at seven Android apps that make use of your phone's in-built sensors to provide some pretty useful functionality.

1. Sensors Toolbox

Sensors Toolbox has several useful tools that allow you to check your device's sensors. If you are buying a used phone, you should use Sensors Toolbox to see if everything is working fine. You can also use it to perform a diagnosis on your existing device.

The app displays sensor data using charts, which makes it easier to detect if a sensor is working. You can check sensors for the camera, GPS, microphone, step counter, auto-rotation, light, and many more.

This toolbox also lets you check the temperature sensor from within the app if you have one. You can set the unit system of your preference, such as metric or imperial. It also displays the overall health of your Android device, like battery health and storage.

Sensors Toolbox has some limitations in the free version. To get advanced features such as custom refresh intervals, sharing sensor data, and no ads, you can upgrade to its premium version.

Download: Sensors Toolbox (Free, in-app purchases available)

2. Altimeter

Altimeter helps you check the altitude levels using your phone. It's particularly useful while traveling. The app uses GPS to give you accurate altitude readings above sea level. The best part is you can use it offline and in flight mode.

Altimeter lets you save the altitudes of your favorite locations and has multiple measurement units, like meters and feet.

You can also change the coordinate system according to your region. In addition, it has a widget that you can add to your home screen to check the frequently updated altitude levels.

Altimeter is a free app but has a premium version with advanced features. You can choose a location on a map, save favorite locations, remove ads, and do more with in-app purchases.

Download: Altimeter (Free, in-app purchases available)

3. GPS Speedometer

GPS Speedometer helps you measure speed in real-time through your device. If you have a broken speedometer in your car, this app will display your speed using the GPS sensor on your phone.

You can change the speedometer's display to simple digits if you want. It also shows you your maximum speed, and the distance covered, and lets you apply a custom speed limit to get an alert when you reach it. The app also has a widget that you can place on your home screen. It lets you check the average speed as well and has both dark and light modes.

GPS Speedometer is a free app. However, to access minimized screen feature, you can subscribe to its premium version, which is also ad-free.

Download: GPS Speedometer (Free, in-app purchases available)

4. Compass

Compass is a simple Android GPS app that helps you with navigation. It works with your phone's GPS, magnetic, and orientation sensors to give direction on coordinates.

Based on your device's GPS location and sensor, the app gives coordinate details such as altitude level, distance, and direction. It also shows longitude and latitude coordinates. You can follow the in-app instructions to adjust your device to increase accuracy.

You can also explore various places, like famous cities, for directions and other details using Compass. Moreover, you can choose from multiple measurement units and a coordinate system to suit your region. The app has a clean Material Design which makes it visually appealing.

To access advanced features like multiple lists, the ability to search places by name, pick points on a map, and find the distance to place in a list, you can upgrade to the premium version of the app. The rest of the app is free.

Download: Compass (Free, in-app purchases available)

5. Cardiograph

Cardiograph allows you to monitor your heart rate, just like the medical devices for heart rate monitoring. You can place your fingertip on the camera and press Start to begin taking readings, or you can use the heart rate monitor sensor if your phone has one.

The app lets you assign an activity such as rest, warm-up, or cardio to each reading. This helps you analyze the heart rates at different points during a workout. You can check your previous heart rate readings through history and can add multiple profiles for other people as well. It also allows you to change the camera to front or rear.

Cardiograph is completely free with no ads or locked premium features.

Download: Cardiograph (Free)

6. Gravity Screen

Gravity Screen automatically turns your screen on or off using device sensors. When you put the phone in your pocket, it turns off your screen to avoid any unintended touch inputs. The app automatically turns the screen on when you take it out of your pocket.

Similarly, you can enable a table sensor and a proximity sensor. It also lets you add multiple finger gestures like single tap, swipe, and double swipe for turning the screen on or off.

Gravity Screen is free but has a premium version to provide you with an advanced experience. It enables you to use a light sensor instead of the proximity sensor and can customize vibration, disable screen lock, and much more.

Download: Gravity Screen (Free, in-app purchases available)

7. Lux Light Meter Pro

Your Android phone has a sensor to detect the light intensity. Lux Light Meter Pro uses that sensor to analyze light levels around you. You can measure the minimum and maximum brightness levels of your mobile screen, the app supports multiple measurement units, and it's all presented with a clean Material Design UI.

Lux Light Meter Pro allows you to store, check, and share your measurements, and you can use it as a fix if your Android phone's auto-brightness is not working.

Download: Lux Light Meter Pro (Free, in-app purchases available)

Test Out Your Android Phone's Sensors With These Apps

Most users focus on the software-based features and utilities of the phone. However, the hardware of your Android device contains a whole other set of useful features. The apps we have listed are safe and pose no damage to your device hardware.

Is your proximity sensor not working? Check out this guide on how to fix it.