Android

Larger, swappable battery. Squeeze for assistant

It's the rear fingerprint reader for me, I use the pulldown action constantly. That and stereo front-facing speakers.

Headphone jack. I've used multiple LG phones before, currently using the LG V60 and seems like Sony is the only way to go in the future, unfortunately.

I loved the IR Blaster on my old Galaxy S4, was really fun to mess with the TV's in public places with it sometimes and was also pretty useful at home as well!

Honestly, headphone jacks are number 1.

Then also, FM radios. Most Android phones had them up until a few years ago, when Apple stopped shipping iphones with the feature, to push more people onto iTunes. I'm not a huge radio listener. But having the functionality during an emergency is invaluable. There was a really bad storm in my country a few years ago. Me and my family had no power and no internet for nearly a week. I would listen to my battery powered radio to get weather updates and to find out what the situation was like elsewhere. I don't understand why that same functionality can't be implemented in phones.

Besides that, removable batteries, sim card and SD card slots.

I'm on a Fold 4 now and I do love the novelty/oddity aspect of having a folding tablet.

But I would love to see the return of IR blasters on most phones and sliding phones for physical keyboards.

Really would love a dedicated camera button that acts as a soft shutter release. Or a button in that position that's programmable.

Phone upgrades.
Battery.. Non lithuim. Flexible and new. []
Flexible screen. Wrist strap or just flexible. []
Fitness/health capabilities. []
Usb 3.1 reversible.. Proper specs [x]
Wireless charging. Using new WiFi microwave to charge phone without mat. Wattup []
Better nfc/Google pay [x]
Smaller screen oled,s than 5.5 []
Better speakers none conduction or ceramic
Encryption []
Bezelless. Screen to screen hole cut out. 2018 []
Solar panel in screen. Sapphire glass. Smudge and germ

This list was created a few years ago.

Some things have been implemented but not all.

Plastic back and a removable/user replaceable battery.

Yeah yeah I know it "feels cheap" but honestly I LIKED when phones were made of more plastic. Now they're heavier and both sides are breakable. Like, the metal backs were fine, but apparently metal backs suck for NFC and wireless charging so instead of giving us some classy Nokia Lumia style plastic they went with glass backs.

Also I keep my phone in a case because otherwise the back is so smooth it shoots off the couch if someone walks across my apartment. It's legit only in the case to add some friction.

Slide out controller, like the Xperia Play. I've gotten super into (at least the idea of) SBC handheld gaming, and there's just nothing quite like the Xperia Play now. Sure, there's bluetooth controllers, but I'm not a big fan of bluetooth, and the majority of the bluetooth controllers make portability a pain rather than it being a sleek package.

Better system font/typeface selection and a way to install new ones. I know it's a petty gripe, but the default android options are few and terrible.

Max 4 inch screen, IR blaster, physical keyboard with speed dial settings for buttons, form factor like the Xperia x10 mini pro, headphone jack, cameraless, LED with customisable lights for different notifications, bonus - built in projector, satellite phone capability,

Ability to use the screen as a display through the USB port so I can debug a lot of my systems at home without needing to carry a monitor around.

Hackability

Native Bluetooth GPS support. I do mapping for OpenStreetMap a lot and the built in GPS modules are just too bad for that. Currently I have to use an app to get my Bluetooth GPS connected. But sometimes this app fails and the built in GPS takes over and ruins my logs.

Headphone jack, apparently..

Officially supported rooting! Makes this less complicated.

Today my wish is for an internal pihole instance running on the device.

Does the alert slider counts as a niche feature? Very few brands provides this.

Niche feature....

By Apple's standards a headphone jack.

By Android's standards IR blaster. Had them in my last 2 phone and man is it nice to turn the volume down on a TV which is too loud in a public place like a Hotel Lobby or a Restaurant

IR emitter . Super handy wen you use old stuf like me like VHS dvd combo crt ect .

I just want a new Droid with a slide-out keyboard

I've had every one of them until the Droid 4 and they never released a new one

One without a damn camera, I swear to God most of the price goes into having "quality cameras" I never end up using.

This is going to be such a stretch and I doubt this would ever happen, but if you could get a decently sized camera sensor on the back of a phone and a mirror less style lens mount...I would sell my DLSR in a heartbeat.

Foldable display - They are still way too expensive!

Metal case - I just loved the heavy Samsung Omnia 7 metal case. It made it unbreakable and grippy!

Removable dual display like in LG G8x, V60 etc. When you need it you can have a beast of a phone with 2 screen or a slim normal flagship.

IR blaster

duck duck go tracker blocking that doesn't use vpn technology

IR Blaster, Headphonejack, SD Card Slot, removable battery

I liked the physical toggle for silent mode on iPhones. Flip/slide-out keyboards were also kinda cool

As far as apps though... I really loved having a good programmable remote app on devices with an IR transceiver. The best one was actually on Palm of all things, and you could add custom icons to a layout and then record inputs from your actual remotes to replay.