Anyone Tried Foxfi on Tmobile or ATT?

[Pinkstiletto66]

I use to use it from my phone to comp with no problems but tried it with a particular app on my ipad and the signal is too weak according to the little pop up message. I eventually plan on switching to Tmobile but was wondering if Foxfi would pull from the phones unlimited data or take from the 500mb allowance. Im looking to buy a portable internet device so im trying to see how much data I would need.