It's an amazing solution. Personally I would go for index cards and a pencil. No noise, no light, and knowing my own tech limitations no stress of having to rem

It's an amazing solution. Personally I would go for index cards and a pencil. No noise, no light, and knowing my own tech limitations no stress of having to remember how to use something in middle of the night. But yours is wonderfully creative solution. It also has possibilities for use in Hospitals and by disabled and others who have severely limited ability to communicate. Lots of possibilities for this.