Lots of people want to use Fire TV for always-on display apps. For example: dashboards, rotating image displays, or other passive display uses. Being able to disable Daydream for Web Apps would make the platform a lot more enticing. It's easy to package a webapp for distribution. Turning it into an Android app just to be able to set a flag is a big step in complexity. So: Please add a checkbox option for "Prevent daydream" that is not tied to video playback. Perhaps if used, show a big disclaimer when that app is started so it's clear screensaver won't kick in.