I have something
very similar to that one. I found that the first time I applied it, I got it a little cockeyed onto the phone and I was unhappy with it. I wish I had pulled it up and re-applied it immediately, but I didn't. The result was that after some time, the bits of the adhesive that was ultimately exposed at the edges because it wasn't on exactly straight got very dirty and unappealing.
So, the 2nd time around (new film), I applied it with a different approach. Of course, I cleaned the surface of the phone with a lens-safe cloth, then, I picked up film very carefully by its edges to prevent fingerprints, then pinched it a bit so that the sticky side bulged downwards from side to side. and then I could very carefully apply the film *from the centre* of the front face of the iPhone. This allowed me to use the holes in the film for the speaker at the top and the Home button at the bottom for alignment against the same features on the iPhone. When I felt like I had it lined up nicely, I then allowed the film to touch the iPhone, which it did in a nice neat line straight down the iPhone's front face. Then, I relaxed the pinch so that one side lay down on the iPhone, then I used my lens cloth and my thumbnail to burnish the film flat onto that side from the centre out so that the bubbles would escape. Next, I burnished down the other side and voilĂ , I was done - PERFECT!
I hope this helps!