The Android version is on sale, too.
$1.99 (excl. VAT) / 2.19€ (incl. VAT)
Tap for spoiler
It was 7.99€ before; don't know about the US prices
And there is also the free (as in beer and in freedom) VoxeLibre.
It was formerly known as MineClone2 and runs on the also FOSS Minetest game engine.