The application streams the part of your PC screen into tablet.
It is useful for cybersport games where map awareness is important: LoL, DOTA, CS, PUBG, StarCraft, Fortnite etc. Just map your in-game minimap to tablet and see it on larger screen.
Also it can be used to map any other important data, like your character's HP or ammo.
Before connection to PC, the PC must run streaming program which is Windows only. Just follow instruction from application. Also the application uses Wi-Fi to communicate with PC so you must have it.