What kind of fiber optic tester do I need?

In my job, we use two multimode fiber optic cables. One has LC connectors and the other has ST connectors. They are run through the ceiling before I arrive on-site, and I want to do a quick check to make sure they work. If there is a fault, I don't need to know specifically where it is; I only need to know if the cable is functional or not.

So, what should I be looking for? I'd appreciate both general advice and specific recommendations for a good, compact (I travel by air with my tools) unit.

Thanks!