[Barty]

I found a free font by SIL called Andika (New Basic). It's a simple sans serif that I surprisingly like. It looks mildly cartoonish but it works for me. I normally use Amasis (slab serif) but it's nice to take a break.

It's been made bolder (probably too bold for most folks) and slightly condensed, the line spacing is more compact. Tested on a Kindle Paperwhite 2.

You can do whatever you want with this, subject to the original SIL Open Font License. Font is named AndikaInk.