I'm going to be the unpopular opinion here, but I think Frog-o-Spheres are cruel and disgusting. To thrive in captivity, African Dwarf Frogs need a heater, lighting, and plants to hide in, as well as at least 1 gallon of water per frog. Furthermore, the stores selling these "gifts" do not have the proper facilities or training to take care of live animals. In particular, Brookstone (which also carries the "tanks") came under fire a few years ago for the huge attrition rate on frogs before they ever left the store.
This is the same as the people who defend gold fish bowls by stating that their goldfish lived to be 2 years old, so it must be fine. That's the equivalent of stating that your human child lived to be 10, so she must have been healthy.