Apple Maps bites right now, so it makes sense that other iOS mapping providers are pushing out updates. I'm not sure the addition of celebrity voices (in the form of Dame Edna Everage, Jennifer Hawkins and Nick Giannopolous) is going to convince too many people to download the latest version of the Whereis app, but even if you don't fancy a 'Wog Boy' moment in the car, it's a solid (and free) turn-by-turn navigation app.
Telstra customers don't get charged for data used by the Whereis app; if you use another provider, keep an eye on your data limits. Whereis is a free download for iOS devices.
Whereis [iTunes App Store]