A lot of families and kids will have gotten a shiny new console for Christmas, and given that Nintendo's new console isn't out until March, chances are that console is either a PS4 or a Xbox One. There's more PS4's in Australia right now, and so there's a good chance that you or someone you know has one.
But part and parcel of the console experience these days is typing things in - names, emails, passwords, the whole lot. And doing so with the controller is a miserable experience. Fortunately, your phone can help.
Once you've got it downloaded and installed, you'll need to make sure your phone is connected to the same Wi-Fi network as your PS4. (If your PS4 is connected via a wired cable, that's fine, just as long as your phone is going through the same network.)
From there, navigate to the Settings menu on your PS4, followed by PlayStation App Connection Settings. You'll see an option called "Add Device" there, which brings up a code when selected. On your phone, fire up the PlayStation App and then hit "Connect to PS4" (it'll be in the bottom left). You'll then be prompted to enter the code on your TV, which should be displaying if you've followed the previous steps.
And that's it - you've successfully added your phone as a replacement keyboard, which is handy in stopping you from having to slowly enter your credit card details or private information. Your phone will also receive notifications, invitations and game alerts from your PS4, although if you want to message users on your friends list you'll need the separate PlayStation Messenger app for that.