go to zagg.com and order an invisible shield, best screen protector i have ever used on any of my phones, and any air bubbles left when you are done will work their way out over the course of a week or two.

btw put youmobile into the coupon code for a discount (20% iirc)

 

Not sure if they make a protector for the stratosphere, but skinomi protectors are amazing.

 

I found that using my finger and my fingernails to slowly push out the bubbles really helped. The few tiny ones left disappeared the next day. Take your time. Use the enclosed tool to push out bubbles, then use finger and fingernail. In all I spent about 10 minutes pushing bubbles.