NV Zilla Slab is a Zilla Slab variant, with adjusted metrics and a 10% glyph size increase. This makes it ideal for digital reading on e-readers.
Using FontForge. You too can learn how to scale glyphs, adjust metrics and generate a font.
I've included the FontForge files in this repository.
As the original font, it is licensed under the permissive SIL Open Font License.