Sketch - Professional digital design for Mac.
Font Viewer - Font Viewer is an application which does exactly that - it views fonts!
Inkscape - Inkscape is a free, open source professional vector graphics editor for Windows, Mac OS X and Linux.
NexusFont - Choose and manage your fonts with Nexus Font.
Affinity Designer - Professional creative software, exclusively for Mac.
Font Manager - Simple font management for GTK+ desktop environments