In Australia on my 13,000+km ride I used a combo of paper maps and HEMA Offline Topo Maps. Paper maps are handy on long trips as when you’re done with them, you can pass them on to someone else; less luggage. I brought my iPhone with me anyway but would leave it on aeroplane mode or just keep it off entirely if I knew where I was going. Battery lasts ages (several days) like that. Offline maps on the smartphone are handy for planning.