Samsung text + with iphone text +?

So my friend and I talk a lot, but she lives in a different country. I have an iphone 4S and she has an ipod 4G. Because she lives in a different country, I do not want to get billed for texting all the time so we use an app called text plus. So we pretty much text on that app. However, she wants to get the Samsung galaxy 4 and we found out that the app text plus gold is on there, but we're wondering if the app from my iphone is compatible with her app from the galaxy

There are many texting apps. KIK is pretty popular

You both can use iMessage on iphone and ipod.

Here is how to use iMessage: http://www.techradar.com/...-5-1055695