[Aenyn]

Just buying a rejsekort (travel card - you put some money on it at some machine with your credit card and it pays automatically when you check out at the end of your trip. It also has a significant discount vs buying individual tickets) solve all the problems for buses, trains, metro, etc. You can also put your commuter card on it if you want, or you can receive a commuter card by text message which would even work with a dumb phone.

But it certainly helps a lot to have a smartphone, mainly for the government messages and the nem id app.