GPS navigation on the bike
Biking long distances means you will need some kind of navigation aid. Paper maps are mostly gone except as a backup measure. Some people use TomTom-like systems specially designed for bikes, but nowadays you don’t need these special tools anymore: your smartphone will do just fine. And it doesn’t have to be the latest 700 euro supersmartphone, personally I use a Samsung Galaxy S4 from 2013 which my kids say is antiquated.