For me its the ‘Knock Code’ that LG had on their phones (I really wish LG still made at least the V series phones)
Basically there was a four-square area and you set up a sequence of where you would tap to unlock the phone. That set of squares was only shown when you set up the code
Then, to unlock your phone, you would tap those areas in the sequence you set up (even with the screen off).
Fingerprint readers are nice, but I really do miss the knock code
Edit: did find this article with a way to do the knock code, but if done wrong, could brick your phone I guess.
Plus, article is from 2014. When I looked at XDA’s info on it (they also being the developers) it looks like development on it is over, but individual modules may or may not still be supported by their devs
I loved how older versions of Android (and afaik iOS as well) could set the album cover of the currently played song as the lockscreen background.
It’s a tiny and maybe completely unnecessary feature, but i loved it.
I think Spotify and YouTube music still do this, you may need to turn notifications on for the app (so that the lock screen player can appear)
The lockscreen player is visible but the background isn’t changing anymore
It’s weird because podcast addict still does this on my android phone but apple music doesn’t…
Custom roms still offer this. Additionally you can even enable Pulse (audio visualiser) if you like.