Currently invite-only. Plaintext/styled-Markdown writing with text 'hiding' with a mouseclick - is this what they're calling folding?

I discovered it as it was retweeted by Mutahhir Ali Hayat, the dev who took over FoldingText before it imploded and disappeared. Hayat and Plain.sh are both located in The Netherlands, so maybe he has his hands in this product, or he just knows the app's developer.

https://plain.sh/

Looks interesting. Thank you for the reference!