F-Droid is great, but it’s only for FOSS. So it won’t host content like TikTok on it.

APKPure

It looks a little sketchy to me, I’m seeing mixed things on reddit about it.

An alternative application you can use to download Google Play apps is the Aurora Store (https://gitlab.com/AuroraOSS/AuroraStore), but I think it still obtains the files from Google Play.