Screenium is exclusively available on the Mac App Store.
A Mac with OS X 10.10 Yosemite, OS X 10.11 El Capitan, macOS 10.12 Sierra, macOS 10.13 High Sierra, macOS 10.14 Mojave, macOS 10.15 Catalina, macOS 11 Big Sur, macOS 12 Monterey, macOS 13 Ventura or macOS 14 Sonoma is required to use Screenium. Screenium is completely optimised for the new M1-, M2- and M3-based Macs.