I recently upgraded my phone at Best Buy. After purchase, I added the Zagg - InvisibleShield HD Glass Screen Protector for my Samsung Galaxy S6. It was readily available at Best Buy and I opted (and paid extra) to have the BB rep apply it to the phone. The shield is a substantive product, not a thin filmy thing. I don't know if it would prevent a crack if the phone took an extreme hit, but I believe that the Zagg shield protects the screen against scratches and moisture, which is why I wanted it. Also, the thickness does NOT impair the phone's responsiveness...another important factor for me. In short, I'd recommend this product. It was pricey (over $30), but I'll keep my phone a couple of years, and I wanted to get the shield applied before I left the store. The shield looked easy to apply and as noted above, I paid extra to have it put on by BB. Next time, I'd do it myself because I had to go back the next day for a replacement because I found bubbles. BB made it right; gave me another shield and a different person took more time to install it. All told, the Zagg shield is great. I gave it 4 stars versus 5 because I think the price is quite high compared to a similar protective screen on my old phone that cost about half the price...and did the job well for several years.