Tank Cohabitants
Springtails are great tank mates for isopods, they'll be a little more efficient at dealing with mold and any intruder larvae like gnats and fruit flies, isopods break down larger debris, the springtails will take care of the rest.
Isopods can be kept with snails, but keep their population in check, if they explode in numbers, they'll outcompete the snails for food and the more protein hungry types may begin nibbling on your snails when they get hungry. They'll always eat any snail eggs they find, so keep that in mind if you're planning on breeding your snails.
Isopods should NOT be kept with millipedes, as millipedes will dig down and begin molting, their shedding exoskeleton is dead organic matter, this will attract isopods to their location, and millipede exoskeletons are protein based and haven't hardened yet when they're still fresh. Millipedes are immobile and defenseless in this state, and the isopods will cause the death of the millipede.
For reptiles, amphibians, arthropods and even some mammals, research each type specifically to see if they are good pals for isopods.