Mix.com was a site I used (sparingly) to save articles in collections for later referral. It was a quasi-social media site in the sense that you could share articles, comment on them and follow feeds.
The site still exists, but if you want to use any of the features it used to offer you now have to download the Mix app and use that instead. I won't be bothering as I didn't use it enough, but it does raise an issue.
In my opinion there's too much push to 'appify' things these days. I'm not against apps per se, and I have plenty of them myself. A native app is a far better way to do lots of things. You might want one for your task manager, or your writing app, or your journaling app, or for a whole host of other things.
But sometimes websites that work perfectly fine in a web browser — and are better suited to a web browser in my opinion — are 'appified' for no good reason I can see. PayPal, Reddit and others often pester me to download their apps, but I don't see any benefit in doing so. I already have an app that runs these things to my satisfaction: Safari.
The cynic in me just sees it as a way the company can get around the various security restrictions modern browsers provide, all the better to allow them to advertise to you and track you.
It's particularly disappointing when they don't create an app in addition to the website, but replace the website with the app, as Mix has just done. It's turning the World Wide Web into a collection of walled gardens rather than the large open landscape it should be.
I expect I'm in a minority with this opinion.