MMS over wi-fi

Since t-mobile's signal is very weak in our house, I have been looking for an app which would allow me to send and receive text messages with photo attachments over wi-fi when available. I'm looking for one which would not require the other party to have the app installed on their phone, and would deliver the attachment as an actual photo and not a link. Is there such an animal? Thanks.

Yes, I think you're right. I've tried quite a few of the apps and everyone seems to require both parties to have it installed. I had high hopes for Text Plus, even bought the gold edition, but unless the receiving party also has the app, the photo arrives as a link only. Most of my family/contacts are using employer provided phones so I don't want them to have to install something. Google Voice keeps promising support for mms, but now I read that my plan (T-Mobile pay as you go) doesn't fully support GV. Anyway, thanks for the reply. I'll also keep looking.