I have an iPhone 5 and am surrounded by iPhone users. With iOS7 there is an iMessage bug that prevents messages from being sent.
Last night I tried this work around and it worked. The only hassle is I needed to re-enter my wifi access passwords.
How to fix iMessage not working in iOS 7 - three simple steps
iMessage texts not sending? Apple promsies fix but here's a simple fix.
Unfortunately, I need to apologize to a few people for my texts not getting through.
After the above work around I could see what text messages were not sent.
Sure there will be a bug fix for this soon, but until then the work around worked for me.