FR80 is on the back of my shingles. Who is the manufacturer?

FR80 most likely has more to with the type of shingle (as in possibly Flame Retardent) or is numbered for inventory purposes. The actual manufacturing information is on the underside of a shingle. There's a sealant strip that holds part of the shingle down, and slightly above that is a clear plastic part with numbers that identify the manufacturer. This won't be visible if the shingle is currently installed on your roof. Hope that helps.