I've been making and selling my electronic social battery pin badges for a while now (https://hortus.dev/products/social-battery) and I'm expanding the range with seasonal versions like a Christmas mood badge, and a halloween themed ghost badge that's coming soon. I'm lucky enough that these projects have gone down well and are making enough money to fund some more complicated (and expensive) projects that I wouldn't have otherwise had the guts to try. Currently I'm working on an RGB digital sand timer with customizable timing sequences so that you can use it for things like the pomodoro technique - I have a working prototype and at the moment I'm experimenting with interfaces for setting the sequences. I wanted to use a combination of buttons and an accelerometer for this but it's not as intuitive as I'd like so I may end up making a small smartphone app to configure it.