I think most modern phones come with one from the factory. I put a screen protector on my previous phone only to realize the next day it already had one from the factory.screen protector
Back in the day I had to do my phone and other people's phones too. I hate hate hated doing this. I effed up so many of those things. I always bought twice as many as we needed, knowing I'd screw some up.had to carefully squeegee on, while in the bathroom running the sink
Actually, here's exactly how I felt about doing it: