Texting/calling PC to a mobile freely

Is there any software that can do this, freely? I’ve just looked at this Chikka but it didnt support my GFs phone, I put a tenner on yesterday and I have �1 left lol.
Anyway, any way to call/text through my PC to her phone, freely.
Answer #1
I know a few people that use this one.
http://www.cbfsms.com/
Euro.