FriendlyElec has a range of boards under their NanoPi brand that might fit:
https://www.friendlyelec.com/index.php?route=product/categor...
The NEO Air in particular is a very compact board using an Allwinner chip, which works pretty well under Linux including such niceties as support for the integrated power management chip.
I also recently got a couple of the Space Cats Jeter Nano boards. They’re more on par with the VoCore, performance-wise, but with a lot of GPIOs on more hobbyist-friendly (read: breadboard-ready) connectors.