I built a really simple app, that allows you to anonymously high-five with a random internet stranger.
I wanted to keep user interaction very restricted, but still meaningful - a high-five is a pretty universally positive thing, and no custom user input means it can't get ugly, as things on the internet usually tend to.
This is why this is the only feature this app has - no nicknames, no messages, no chat. Just a high-five.
I use IP geolocation and display the country of your co-high-fiver as a minimal kind of framing that it is indeed another person that is interacting with you.
I actually managed to get it to around 100k unique visitors in around 10h and a constant ~800 concurrent users, with very positive feedback on reddit.
It's implemented with websockets using Crystal + Kemal as a backend.
I will not be monetizing this in any way, and I will not be adding any new features.
I think it turned out pretty great, so I'm showing it off here - for some light-hearted fun.
In his case, the guard clause is completely appropriate, because "super" is "the rest of the method" the guard clause is protecting. It's not a filter method, it's a selective render method.