Is it possible to text an iphone with no service?

My friend has an iphone2 or 3 but he didn't pay the bill so its off but there's excellent Wi-Fi in his building. So I was wondering if there was an app that would let my andriod text him and it get through even if that app isn't on his phone

Yes it's possible, I text with my iPad all the time and it only has Wi-Fi.

On my iPad and my android phone I have a free app called text me that let's me send texts back and forth without using anything but Wi-Fi. There are lots of apps available that do it that's just the one I like.