Send SMS through internet to another country I came to Europe from Canada for a month, but I want to keep in touch with relatives and friends back in Canada. Assuming I have WiFi access on my Android, how can I text them, and be able to receive texts back? Texting overseas would be too expensive for both me and them, so I must find a way to do it through WiFi, but they would receive and send actual texts.   

I have a Nexus 5 with Android 4.4.4.
I don't know about Canada, but here in the UK some carriers have apps that let you use your WiFi connection to send texts and receive using your normal phone number. I'm not sure about using this overseas but you could probably use a proxy (like Hola) if this is blocked. Even if an app exists but you cannot receive texts with it then this is generally free when roaming because you have no control over who sends you an SMS.