FontForge - Free (libre) font editor for Windows, Mac OS X and GNU+Linux
Marvel for iOS - Rapid design and prototyping for the iPhone and iPad
TruFont - TruFont is a font-editing application written with Python3, ufoLib, defcon and PyQt5.
Peetch - The last PowerPoint Pitchdeck you’ll ever need
FontCreator - This professional font editor allows you to create and edit TrueType and OpenType fonts.
Keynotopia - Prototyping straight into Keynote or Powerpoint