Are there any Canadian texting apps with reply numbers?

[affirm]

So I currently live in Canada but I will be moving to the UK after the summer vacation. I recently got myself an HTC One X and am looking for an app that will allow me to send texts to Canada through data and have my friends in Canada reply the text directly to a number. I know that there is one on iTunes called Textnow so I'm looking for a similar one in the android app store. I have no problem paying for the app as long as it is unlimited texting (pay per month or one time pay)

Does anyone know any?
Thanks