As follow up on the topic, Raspberries Pis
are all the rage lately but here's an interesting competitor...
The PINE64 can be loaded with the latest Android software built in, or you can upload the latest version of Linux or Windows IoT. Out of the box, with Android or Remix OS installed, you immediately get access to over 1.6 million apps on the Google Play market, downloadable in a few clicks.
Main specs are a 1.2 GHz Quad-Core ARM Cortex A53 64-Bit Processor, dual core Mali 400 MP2 Graphics, DDR3 Memory, integrated display engine with HDMI 1.4a, and Gigabit Ethernet Port. The PINE64 is available in 512MB, 1GB, and 2GB versions, with prices ranging from USD15 to USD30.
For more info, check https://www.pine64.org/
For a survey of various System-On-a-Chip (SOC) offers, see http://www.eetimes.com/document.asp?doc_id=1328008