disroot also offers xmpp service.
looks like it uses the API, the about page says:
Uses Twitter’s unofficial API (no rate limits or developer account required)
I’m not really sure what unofficial means here, but I’m guessing it’s referring to Twitter’s private APIs.
here’s an issue on github:
https://github.com/zedeus/nitter/issues/351
another one:
https://github.com/zedeus/nitter/issues/379
this just looks like a client rather than a frontend, your browser still connects to reddit, unlike teddit which proxies everything from reddit.