"EmbeddingGemma 2 is made by Google DeepMind and released under Apache 2.0. This is an independent project, not affiliated with or endorsed by Google."
The reference to Apache 2.0 on the page refers to Google's base model, not this app. Based on the page alone, the app is free, but the source code is not open-source.
Torrent trackers. Basically the index that let's your search for and find torrents, private ones are invite only. Common for rare music or better sources of films, and so on.
A "private tracker" is basically a speakeasy for media piracy.
It's BitTorrent, so it's peer-to-peer, but it's exclusive and secretive to avoid letting in surveillance bots that get everyone threatening letters from their ISPs.