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
IR transmitter, removable batteries (but they will come back), the notification LED.
I had the HTC One, which not only had an IR blaster, but an IR Recorder. So if you had a remote with a nonstandard IR signal, you could record it and the replay it. It was truly wonderful. And being able to control TVs in the office gym with my phone… chef’s kiss
I like the concept of IR blaster but the one I had was in Samsung Galaxy s6 (or 5 don’t remember) and it came paired with a HORRIBLE app that tried to do its darnest to datamine your viewing habits and it’d do push notifications 5 times per day with just crappy ads. I really hate all the ad spam on Samsung phones back then. Idk if that’s still the case
I missed the iR blaster so bad in my phone that i ended up buying a USB-C IR Dongle in Aliexpress, and i carry it over in my keychain. The need to turn on projectors, AC’s or simply turn off TVs in Shopping malls or Stations was so much to justify the purchase.