Shut up my roomie phone

Hello,

Thanks for reading, i go direct to the problem.
While ago my romie started hearing some podcast at the night. The think is he usally turns the volyme to max level then he forgets to close the app and he falls sleep. Our rooms are to close and the noise is so irritating i can't sleep. Some times i go to his room and turns his phone off, but this is strange to enter his room when he sleeps. I ask him to stop but the problem continues.

He acepted to use a remote control of his phone in my phone. So i am asking fot a method or app that i could use?. I only want a eay to turn the volume off when he forgets to do it. Is there any app i can use?

Thanks