What do you do for authenticator apps?

yes they do
they block all pictures

Yes. And in a perfect world it still be that way.
The point of this article is to give a realistic solution.
Plenty of bochurim (or any erliche yidden/noshim tzidkoniyos) who would never listen to goyish music have Spotify which sadly makes their eyes vulnerable to terrible things. Zing or 24six really isn’t much of a compromise for them as much as giving up a smartphone.

I didn’t know they. That’s actually really cool.
Do they block cover art as well?

For those who wish to be enlightened, inspired and weaned off the hype of thenew age so called jewish rock and roll music – see here for a strong detoxification by Rabbi Yossi Paltiel.
https://youtu.be/Jemg9PybtMI

I run a web based business and I have plenty of internet access – at my office. What I carry in my pocket is to make and receive phone calls.

Nobody really needs a smartphone. I’ve traveled, taken cabs, ordered food and pretty much done everything without one. You print out QR codes and boarding passes and you’re fine. Just call in for a pizza or a cab instead of Uber. Instead of Waze just use printed out directions, a Garmin GPS and very occasionally get stuck in traffic once in a very long while. It worked fine in 2004 and still does today today. Some of the most productive people I know do not own smartphones and they are doing more than just fine.

So, perhaps it is time to consider freeing oneself of the smartphone altogether and this way the whole kosher vs non kosher apps issue becomes moot.

I noticed that recently Spotify decided to insert pictures of פריצות in lyrics of popular Jewish songs (like Avremel Fried’s popular א גוטע וואך),

It’s time frum yidden get rid of Spotify

And those who want to use an app to download songs, can download: zing

Or: 24six.