Beanback
I’m still working on my side project, ‘Beanback’ (https://beanback.space/). It provides digital loyalty cards for cafés (think of an electronic version of paper stamp cards). However with zero apps or customer signup, instead loyalty passes go straight into Apple and Google wallets. It’s written in Ruby on Rails, which I’m enjoying learning. Still a bit rough around the edges, though it’s free for now so I’d be grateful for your feedback. Thanks!