I'm shocked that this setting isn't available so far although it was mentioned many times before.

Portal with small kids isn't reaching it's main goal of having a fun call with the family.
My toddler keeps ending calls and playing other features while talking with our family so I had to put the portal in a high position so that she won't be able to reach it, but because of this the camera isn't able to catch my toddler when she comes closer to the shelves and I always have to try to keep her within the range of the camera for my family to see her, which means that the main goal of the device is totally lost and I can't use it for the reasons I bought it for.
It will be a huge difference!!!

This setting is available in iPhones and called "Guided access" it allows us to keep the toddler within a specific application and it allows us to lock specific parts of the screen while using this application and even lock all the screen if needed.

We need this setting in Portal too!!