How many African countries currently deploy Cat 3 ILS?
This answer has a list of all airports with a Cat III ILS system.

Africa was assigned ICAO region codes D, F, G and H, so you can just look for ICAO airport codes on the list starting with those letters. The only one I see is "GMMN (MOHAMMED V INTL) on runways: 35L, 35R". That name wan't familiar to me, but a quick Google search says that GMMN is Casablanca, Morocco.