Textfree by pinger issues?

So there is this kid i want to text and he doesnt have his phone right now and i dont have texting at all and he has a texting app on his ipod touch, and i dont know which one it is, but i know the number. but, i dont know the area code or service provider since it is on an ipod texting app. but i want to text him and whenever i do it always requires the service provider and/or area code. how do i do so?Textfree by pinger issues?
i dont get you when you say you know the number and you say it requires a area code.

the texting apps out there are

textfree

textnow

dmv nc