Look up word etymology. Also kanji and language studies. You don’t need a language program like memorize, you can just study words.
Listen to ABC Listen podcasts and live. Listen to my music. Listen to audiobooks.
Camera. Photos and occasional video. I have been photographing some of my garden, same plants each day to show growth.
Stay in touch with friends and family on Telegram, or just with a phonecall.
I know people who use their phone for money but I don’t do that. It does contain my drivers licence though. I prefer the licence itself, that said, I don’t want to hand over my unlocked phone.