Thank you for sharing your idea! The "lock mode" feature in Google Forms is a special tool designed specifically for Google Workspace for Education and managed Chromebooks. It works because Google Forms is deeply integrated with the Chromebook management system, allowing it to restrict students from accessing other websites or apps during an activity.

Currently, this type of functionality isn’t something external websites like Lumio can achieve because it relies on direct integration with ChromeOS's administrative tools. While it’s not possible at this time, we will continue to monitor changes in technology that might make similar features more accessible in the future. We appreciate your feedback!