I have a Bodyguardz kit, which is similar. The screen protector piece is worth putting on the phone, because then you know that keys and coins and all sorts of other nasty, evil objects won't be scratching it.
Here's a quick photo of my phone with the iQase FILM on it. It's the best position/light I could get it at to show how visible the shield is. You can see it's there because of the oval around the ear speaker where it's cut out.
Otherwise, it's just that clear and shiny, feels like glass, and if you don't hold it at an angle like the photo with the screen off, you can't really see it at all (you can't see the edges on the sides at all, it's really just the cut outs that are visible if you try hard.
As for install, watch the YouTube video linked on their page...
I purchased the crystal film from the Apple store. It took less than 2 minutes to apply. This protector is awesome, anyone that holds it can't even tell it is there. It has a great feel to it as well. My favorite part though is after one swipe across my shirt sleeve it is smudge free.