I'm a huge fan of running web servers in the house - but they don't have to be connected to the Internet to be useful and fun! An Apache instance on my always-on box in the basement [0] serves an incredible number of uses and can be connected to from any computer-like thing on my home network. Old-school CGI scripts can be written almost as quickly as terminal scripts and HTML forms make super quick interfaces. A home web server is probably STILL the easiest way to get files to heterogeneous computers and phones and tablets and...

[0] https://ratfactor.com/setup2

Our (decades old) house web server has a home page with useful links, and in particular to a simple wiki on the same box. Without any pushing (that never works) the rest of the house has slowly learnt to use it, so the calendar, the wish lists, the pet histories, holiday ideas, all sorts of stuff are on it. The server also hosts simple apps like JS clocks, calculators and of course the [0] pewpew attack map (maybe a little less funny these days, but hey).

Edit: ref CGI, there's a few apps on there that do that as well (e.g. fish tank temperature monitor). Nice thing about a small private network is being able to do CGI scripts in bash/whatever without having to worry too much).

[0] https://github.com/hrbrmstr/pewpew