Access here: https://subtitle-app.vercel.app/
This is an open-source application to play a subtitle file as if it were a video.
It supports SRT files or ZIP archives with SRT files inside.
It can be useful to enjoy content in a second subtitle language.
There are similar tools for computers such as Language Reactor extension but I could not find any good tool that can be used with your TV.
With this app, you can play the main content via the regular streaming app on your TV, then open up Subtitle App on any old phone/table, queue up the subtitles file and place it next to the TV.
I have used it to watch some K-dramas with my partner as both of us have different preferred languages for watching TV, and neither of us know Korean.