Max Protractor & Black Sensor Lite

This Max Protractor app makes use of your phone’s camera, gravity sensor, and magnetic sensor to deliver that most important of things – angles. You can measure inclines, planes and plumb angles, and we’re guessing that this is another of those apps which, if you need it you need it. Apparently it only shows around 5% error compared with expensive laser equipment, which is reassuring if you’re building a hotel we guess.

Black Sensor Lite is a driver assistance app which uses the camera and accelerometer of the handset to provide lane departure warning (valuable if you’re driving while tired), motion detection and black box recording if an unfortunate event occurs. There’s also an emergency contact number feature which gives one button access to family, friends or insurance companies if an accident occurs. The free version is time limited.