Display Tester is a very useful app that lets you easily test the quality of your device's screen. This tool helps you detect problems with your screen, avoiding compatibility problems with certain games and calibration errors when using other types of programs.
Although the app comes with a huge number of options for carrying out specific tests, this free version only has two useful tabs (the rest can only be used by 'pro' users). The two broad categories you can use are Information and Display Quality. In the first, you can find a lot of data related to your device's screen, like size, number of pixels and their format, and density, among many other values.
With this tool you can detect dead pixels; test the color using contrast, gradients, or saturation tests; utilize gamma calibration using grey, red, green, or blue backgrounds; view angle tests; repair burn-in with scrolling black and white bars; and even test multi-touch performance. The app's pro users can perform font style tests, measure the DPI manually, and calculate dead points or the DPI.
Lastly, Display Tester has an option for sending tests directly to Chromecast so you can also find errors with your television screen without using complex configurations.