I’ve noticed that there are a few fake websites hosting modified versions of libretube. These modifications are likely malware and are dangerous.
Please make sure that you only get your apps from trusted sources. I would recommended a F-droid but I’m sure there are other options.
I wouldn’t even trust the Google Play Store, its notorious for having problems with malware, and full of fake apps impersonating trustworthy ones. This has happened to apps like NewPipe several times.
Overall, only source I’d trust for apps is F-Droid, and maybe GitHub/GitLab/Codeberg, depending on how much I trust the developer and the app.