Easily notification light. People always say "oh, it's totally obsolete with always on displays". But with a notification light I could focus on other stuff and the blinking light got my attention better. With the AOD, I always catch myself glancing at my phone. Also, the light's color clearly indicated which app caused the notification. I had White for calls, Green for Whatsapp, Yellow for the ebay app, Red for GMail and so on. "You can do all that with an OLED screen! It only lights up the pixels that-" Can you, though? All apps that I tried were utter garbage. Buggy performance, very battery hungry and very cumbersome to configure. I don't know if custom firmwares actually have that feature in a usable state nowadays, as I cannot root my phone anymore without losing core functionalities like online banking.

Yeah, everything tends to go to shit with time. I miss my Galaxy S2.

Apparently nearly everything I look for in a phone. Others have said IR blaster, side squeeze, notification light, and pop-up front camera, all of which were amazing.

I'd add an unlocked bootloader (I bought it, it's my phone to do what I want with), removable battery (hello instant charging), and a small form factor (so sick of needing two hands to do anything).

Not so much a gimmick, as much as something that seemingly went extinct that I miss: rear fingerprint sensors. I loved them on my Nexus/Pixels, and the in-screen one on my 6a is way less consistent and convenient.

Also it flashbangs me when I try to unlock my phone at night.

Does IR sensor count? I loved that on older phones so much.

Idk if this is a gimmick but I love swiping on the rear fingerprint scanner to pull up/down the notifications and quick settings. I also got an app that lets me swipe left/right on the sensor to adjust the brightness.

Material You. I wondered why they wasted resources for ... colors. But it's so nice to have a consistently colored UI across apps and across dark/light modes, and I wished that more apps would support it. Also, those pastel colors are less stressful for the eyes than the previous grey/blue.

I know it's not everyone's taste but I really like it.

On my motorola: quick shake side to side to enable flashlight. So easy to use, it's become second nature. I'll have to find a way to replicate that on the next phone I get.

That pop up camera on the OnePlus 7 pro.

That thing was cool as fuck. My roommate got the phone and I was VERY jealous even though I had a OnePlus 8T at the time.

It's been gone for a while now, but I really liked the IR blaster to use as a secondary remote when you can't find the remote because your toddler was playing with it. Dammit Susie!

Front facing stereo speakers were nice.

IR blasters. They were nice as a little pocket universal remote.

The air gestures that Samsung put in the S5. It was a gimmick, but a useful one, since you could use it to control things without having to fiddle with the screen.

Also the screen-off gestures on the Oneplus 5. It was great for turning the torch on or opening apps without having to faff about as much with the screen.

Nokia N95 flipping both up and down. I really liked those music player buttons when flipping it down

Removable battery, micro SD, sim slot etc

To show how old I am, a phone without a physical keyboard.

Tablet computers. My thoughts on the first iPad were that it does everything a laptop, an iPod, and a Kindle all do, but worse. Next thing I knew, they were everywhere. I think traditional laptops are making something of a comeback, though.

My wife has an iPad and after using it for a bit, yeah I get it.

Can't say I love the feature but the front facing camera getting "integrated" into the screen isn't nearly as annoying as I thought it would be.

Fingerprint sensors

Idk if this counts as i dont really involve myself in a lot of discussion, but MAN do i miss two button navigation. it may still be present in some other Android distros but on Graphene an update removed it for me a while ago.

I have a samsung flip. I cannot tell you how much I love this phone.

the IR Blaster, absolutely loved it and still do

Workspaces in Linux window managers. I thought it was a dumb idea at first but I tried it and found workspaces are great.

Allo was the best messenger. So many useful features

Apple’s 3D Touch on iPhone. Force Touch or whatever they called it. The ability to hard press to get something like a right-click. Wish they’d kept it. Used it every day for placing my cursor.

The active edge squeeze feature on the pixel 3. I loved being able to gently squeeze the sides of the phone to trigger google assistant.

My old LG phones had power and volume controls on the back, rather than the side. Great for picking up the phone with either hand, and it was easier to mount in a phone holder (no buttons to accidentally mash).

Rear power and volume buttons.

To this day my favorite phone remains the LG v10. It has nice metal rails on the side, a rubber removable back, sd card slot, aux port with a high end dac, wide(er) screen, and buttons on the back of the phones right where your indexed finger would rest when holding it.

Figure print sensor on the button didn't work all that well, but worked better than this shit on screen reader. The buttons being on the back meant your could just grab the phone in anyway with out worrying if you're gonna Power the phone off, turn the vol down, take a screenshot, etc. This also meant getting it knot phone holders was almost never an issue.

That was the closest an android phone got to perfection. After that they started trying to follow tends and phase out the good parts to the point of leaving the Android market entirely.

FM radio. Also my old Motorola had a "karate-chop to activate camera" which was very useful

The ringlight on the bottom of Xperia U.

IR blaster, removable battery, MicroSD slot, analog headphone jack, unlocked bootloader, stylus. The Note 3 was the peak of android phone design. I'm using an S22 Ultra nowadays because of all those features I'm a huge slut for the S-Pen, even to the point of sacrificing all of the others... But I'd love for the rest of those to make a comeback.

Power button fingerprint sensors. I had one on my S10e, and I loved it - with the way I held the phone, my thumb naturally rested on the power button, so it was pretty much auto-unlocked.

Now they seem to have fallen by the wayside in favor of in-screen sensors - which are cool, but ever-so-slightly more cumbersome. Ah well, still better than facial recognition.

Keyboards, optical scroll, and IR blasters.