Wojciech Sura (forum user spook) has made a very useful tool for creating and editing fonts for the ILI9341 display

Until now, the only way to get custom fonts in the ILI9341 display has been a converter script.  Now you can actually create & edit fonts with a beautiful graphics editor.

This useful app includes a number of features, including:

• Create font from scratch (specify size, default offset and delta)
• Create font from existing system TTF font
• Easy to use editor with zoom (mouse wheel) and scroll (middle button) as well as continuous drawing
• Preview the whole font or specific string
• Batch glyph operations allows quick tweaks (for instance, batch offset change)
• Quick optimization of character or the whole set (removes empty columns and rows while keeping character’s position and size)
• Export to ILI9341_t3 format (.h + .cpp)

The editor is available in this GitLab repository.  It does require Visual Studio 2017 to build.  If you don’t have access to Visual Studio, spook has posted a build in this forum thread.