Apricity beautiful Linux distro based on Arch

Why is Chrome, a proprietary software packaged when there is a practically equivalent FLOSS software (Chromium)?

Or, the more general question -- how Pacman packages and Apricity apps relate to each other? The answer seems to be not straightforward, as if Apricity apps were just sugaring for a subset of the Pacman pkg set, then Chromium would be packaged (given Arch ships Chromium, not Chrome).