Recently i've been playing pubg mobile a lot. If before i charge my device once a day, now i charge my device twice a day. Does it bring any harm to my battery for a long term usage?
Battery will be fine. One way to care for it is don't charge it above 75% anything about that uses more wear. Accubattery is a great app for battery care if you have any concern.
I have 1 more question, didnt this kind of app drain battery and slow down performance as well? I havent install like optimization app or something similar to it for quite sometimes now.