Can someone recommend some cheap ESL (as mentioned by other comments), that's easily hackable (as in a push an image to it without much troubles)? Many need pro

Can someone recommend some cheap ESL (as mentioned by other comments), that's easily hackable (as in a push an image to it without much troubles)? Many need proprietary base stations, some use NFC, but I'm looking for something with Bluetooth or ZigBee (or similar). Basically I want simple frame that would update with calendar events (or something), so NFC is not suitable and I don't want to buy expensive base station with lots of extra cruft (especially for one tag)