Seeed Studio’s reTerminal Sticky is a small, versatile device that combines a 3.97 inch E Ink touschreen display with an ESP32 microcontroller and magnets. But it’s also a small battery-powered device that you could use a tiny eReader. On the bright side, the reTerminal Sticky is one of the most affordable options to date. The reTerminal Sticky measures 106 x 65.5 x 7.3mm (4.2″ x 2.6″ x 0.3″) and weighs 70 grams (2.5 ounces). But if you manage your expectations for a $50 gadget, it seems like a pretty nifty device.