I been using the cheapest Amazon tempted glass screen protectors for years! At $3 for 3, it pretty sweet deal for me since I install the protector just after taken off the iPhone screen wrap. No alcohol and linen dry routine. Takes me a good 4-6 seconds. 2 seconds to align and 2-4 seconds to smooth out the bubbles.
I going to buy the new technology of rounded edges and edge to edge technology this time around since this type of screen protector has gone down in price from $49 to now $6 for 3 and positioning frame is thrown in too! I might try sapphire glass if I can find it cheap like under $10. I always see in the past $79-$90 for one screen protector totally insane!