I think I may have found a solution for the glass crack on my Nexus 4.
I had been searching around for a replacement back, but I didn't want to possibly have the same issue again. So while reading
http://mobilesyrup.com/ today I saw an add for a product called DBrand.
http://dbrand.com/
Anyway, check out the site. They have lots of perfectly cut skins for the Nexus 4 and other Android and Apple devices. Even game controllers! They're out of Canada and the skins look to be a good price. About $9 each, plus shipping.
I'm going to post this exact post in the Nexus thread, as well.
Here's a quick review and application of the product:
I think the best part is how their skins fit EXACTLY to the phones. No extra stuff not covered. Search for other review on YouTube, and you'll see what I mean.
BTW: Wireless charging STILL works with the skin, as I saw on another review of the DBrand skins.