Because people outside the US don't have access to Google Voice.

We built this because our experience with Google Voice was awkward. Having multiple phone #'s didn't work for us.

This basically mirrors the SMS activity/stream on your phone, onto a Chrome extension.

If you're using multiple numbers with Google Voice, you're doing it wrong and missing the entire point.

"Mirroring SMS conversation in a chrome extension" is precisely what Google Voice does. I can receive and reply to texts from any keyboard with a keyboard, or from my phone if I'm AFK.

You should try this out for a few hours and see the difference.

Just the fact that it gives you HTML5 Desktop Notifications with easy way to reply, and syncs with your actual texting stream on your phone (not GV) makes it worth looking at.

> syncs with your actual texting stream on your phone (not GV)

I don't have an "actual texting stream". My texting is all 100% free and through my Google Voice number. Google Voice offers me more features than this application can by the very nature of how it works.

Because everybody I know has my real phone number.

If that is indeed the only thing stopping you from using it, you can port your existing number to Google Voice.

http://googlevoiceblog.blogspot.com/2011/01/port-your-existi...

Our view is that many people don't want to break out of their existing contracts with their carrier -- which one has to do when porting their current # to GV

Many people are stuck in long term contracts with their carriers. When you port your #, it breaks that contract.

This is definitely not for everyone, but if you look at the comments from users, you'll see why people are using it:

https://chrome.google.com/webstore/detail/dkfhfaphfkopdgpbfk...

is this available worldwide? Google Voice isn't so that could be a reason