Ahh, I see, I've never used a screen protector on any iPhone I've owned, so can't really comment on those.
And never needed one either. Unless you are really rough with your iPhone, I'm not sure its necessary.
I've not used that one but I have used Zagg on my last 3 iPhones. I pass mine on to a woman with 4 boys and she has needed the protectors. And they worked. If it is just you and you are careful with your small electronics you might not need one.
No. There are no screensavers for iPhone.
The iPhone will turn off the screen when not in use after a certain time. You can set that time in Settings->Display & Brightness->Auto-lock.
Oops, I am using the wrong term! What I meant is do I need to use a screen protector. I have seen glass screen protectors by Omoton. Are these any good?
Do I need a screensaver for my new iPhone 8 Plus? If so, what is a good one?
