It’s not of much use to most people, but should you want to access the hidden service menu to test your Satio is working correctly, you can access it by pressing the following button combination in quick succession:
Red, Green, Red, Red, Green, Red.

The options you get there include things like display tests, total call times, vibration tests, MAC addresses for the wi-fi and many more. If you ever want to buy a second hand Satio, it’s a good way of making sure it’s in full working order.