If you want a board close the size of the Raspberry Pi but with a bit more oomph under the hood you’re spoiled for choice.
The latest souped-up, single-board computer to be announced is the Odroid-N1, which packs similar specs to the $449 Samsung Chromebook Plus into what is promised to be a $110 board.
The board runs on a hexacore processor backed up by 4GB of memory, two USB 3.0 ports, Gigabit Ethernet, runs Android 7.1 and Ubuntu 18.04 and can be hooked to 4K displays via HDMI 2.0.