Wont work outside the house?

If Im at work can I take a pick on my kid?
So far I cant get it to work, unless Im connected to my wifi at home. As soon as I leave the house with my cell phone, it drops the connection with my sons iPad.
Is it only made to work within the same wifi?
-Otherwise it works great within our home.

Flabdala about Cloud Baby Monitor, v4.0.2