What to do with an Android spare smartphone (no sim card)?

Turns out Australia is removing 3G support nationwide and that means I have to upgrade. I've had my phone for at least 4 years but it runs well, I wasn't planning on upgrading for at least another year.

I want to keep using it, but I'm not too tech oriented so my thinking has been, " I can play music with it, some games, videos"...And that's fine. But perhaps some of you guys have more creative ideas? Curious as to what would you recommend.