As others have said you are likely to find it on sites listed on our wiki, do note that these will most likely be CAM copies since the digital release will only happen next tuesday(18th).

edit: Seems the rumors of July 18th release was wrong :/ and it will only release early august source: https://www.digitalspy.com/movies/a44035174/across-the-spiderverse-streaming-watch-online/

You can absolutely torrent on Android, I exclusively torrent with my phone. Uses less power to just download a file for a while

You can find many streaming sites in the wiki

...just torrent it. LibreTorrent from FDroid works perfectly fine with Riseup VPN

https://movie-web.app/media/tmdb-movie-569094

Still the cam version, but the picture is good even though the sound has issues.

https://movie-web.app/ if you want to watch something else.