As it's too hot to do anything outside today I've had a quick play with the Vic Emergency app.

Get it here: https://emergency.vic.gov.au

It actually has really good topo maps with trails marked with names etc.

Doesnt look like you can download maps for offline use buts it's very handy when you're in mobile coverage area.

Maps render very well on the iPhone and iPad native apps and locate you of course.