Ntablet has announced its eponymous open-source tablet, a device that supports Android and Linux. The Ntablet can be connected to external sensors and actuators, while it even has a replaceable processor.
https://www.notebookcheck.net/Ntablet-A-tablet-that-comes-with-an-interchangeable-processor-and-that-should-also-appeal-to-Raspberry-Pi-hobbyists.452985.0.html