Cordoba lunch app or unlock screen or wake up screen on android

Question

im working on a signaling application with a corridor, and the fact is that I need to wake up on the screen. I was looking for some solution, but could not find it. Can someone tell me what to do? I know that you can at least wake up on the screen, because the Snapchat application has this feature.

I will be grateful if someone gives me even a little hint :)