Things are complicated. As a policy, I wouldn’t want to encourage grandma to be going to any web site to download software. Grandma should probably stick to the App Store. And personally, I would way rather install github builds than downloads from ‘official’/independently maintained web sites. Especially in the case of free / open source projects, sometimes cash constrained. Security is hard.
I’m not super knowledgeable about modern video players- I do like Infuse, which is in the App Store.
