I've honestly never heard of Tildes til this post. As far as I can tell since there's no API he's just scraping html which is not ideal, but still it's worth checking out. I love that developers are still determined to make 3rd party apps.
That seems like a pretty bad platform to develop an app for then lol at least APIs try to maintain backwards-compatibility (and give you only the data you need in an easier format), I can't imagine that being sustainable long-term.