The MHL Checker app is an Android tool that can be used to check the HDMI connection on your smartphone or tablet. The app is designed for Android devices that have a built-in microphone and can also be used to check the connection on devices that have an external mic. The results of the test will appear in a text box, so you can read them and decide whether the connection is good or not.

The app is very easy to use, and you don't need to do anything special to use it. All you need to do is open the app and click the "Check" button. After that, you will see a test screen that will ask you some questions. The app will then take some time to analyze the device and will give you the results in a text box.