An idea: minimalist Linux teleprompter

As I have a YouTube channel, I use lots of tools that help me with filming videos. One of such tools is a teleprompter. This is a device that helps me remember key points that I want to talk about without looking sideways.

Before recently, I used my phone as a teleprompter. But since Apple now refuses to accept my cards (due to region locking), the phone teleprompter stopped working. So I was thinking -- maybe it's possible to do something simple that would work on Linux? I mean, there are small external HDMI displays you can put into the telemprompter instead of a phone.

The only problem is that there are no simple teleprompters that are lightweight. Here are my requirements:

I don't think I'm asking for too much. It can really be done with just a little bit of code. Maybe I'll even take it as a next side-project.