All my projects seem to suffer from feature creep.
This router I built out of necessity for my dorm now has a HD44780 LCD.
As mentioned in the subheading, I used a UMTS modem I got for free with my contract, an old TP-Link WLAN stick i used to play with in Kali and the Pi B I brought to Uni as a media player for my dumb smart TV. The screen I had at home in my box of unnecessary stuff, so that was not there from the start.
add b.a.t.m.a.n. and power offgrid