Over the past few months I've been developing a small 7-segment LED "sidecar" display board for the Raspberry Pi
I've now launched it on Kickstarter as the "Joey"!
See the Kickstarter project page here
It's a 4-digit 7-segment LED display that sits off to the side of a Raspberry Pi (any model) - the idea being to have a simple display that's still visible when an expansion board ("HAT") is mounted on the Pi, and that can co-exist electronically with just about any other expansion (it doesn't use any dedicated GPIO pins - it sits on the I2C bus, along with any other I2C devices you might have).
It's designed for displaying numbers (e.g. sensor readings or a count) or the time, but I've written a Python module that also lets you display 4-character words. It would be cool to have a scrolling message display, but I haven't developed that (yet... - but maybe someone else will?).
And it has some jumpers that your program can respond to - they are kind of a "because we could" addition, but still nice to have.
If you're interested, please take a look!
And if you think others might be interested, please share...