Whitestone Dome Tempered Glass (UV Install)
Next on our list is something you probably have never tried. This is a brand known as Whitestone, who sells a Galaxy S9+ tempered glass screen protector and a UV light that "cures" the glass into place. It's crazy technology, but it works.
This isn't for the faint of heart but it's totally worth the protection. WhiteStone uses a special liquid installation process where you manually place the phone in a tray, tighten the screen protector in place, then use a UV dome light machine (USB powered) to actually "cure" the liquid to the screen. This provides a solid install with no touchscreen issues, raised edges, or problems. It's the best on the market. The video above is a review of their product for the Galaxy S8. It's not permanent and can be removed if necessary, so don't worry about that.
Basically, where most glass protectors don't fit right or have gaps on the screen and touch sensitivity fails, this one won't. The liquid fills in the entire area, then curves the glass to the screen. These typically run around $60 but are often on sale for $45, which is still less than brands like ZAGG.