Just go for an iPhone. Talkback is very inferior and buggy compared to the capabilities of VoiceOver. Personally, I have an iPhone SE, as I dislike the form factor of the 6, 6s, and the 7. It fits my hand perfectly, has a great amount of storage, and is quite fast.

When I was visually impaired, I always had the invert colors function set to a triple-tap of the Home button, also known as the accessibility shortcut. Zoom was accomplished with a three-finger triple-tap on the screen, plus if you held your fingers down on the third tap and slid them up and down, you can control the amount of zoom in and out. Even using an iPhone 4 back then worked very fast with these features, especially as you got faster and faster at using them.

Ultimately, most apps built for the iPhone, unless they have quite a bit of custom controls and when the devs don't know any better, most apps are natively accessible from the get-go. There is only one version of VoiceOver and it only changes with most iOS updates and point releases. Talkback changes on every device depending on how the hardware manufacturers decide to incorporate it into their specific build of Android, making the experience inconsistent across all Android devices.

All in all, VoiceOver is consistent across all iPhones, works faster and more natively than Talkback, plus more and more developers are beginning to hire accessibility specialists like myself to make their apps more accessible overall. The process to do this is much smoother for iOS and takes forever with Talkback apps due to all the hardware differences from all the Android manufacturers and the slow speed of new update adoption from Android users. Give the iPhone another shot, it will ultimately be more worth it in the long run.

Hey oh! I also have KC and am legally blind. I use the iPhone and it's great. I have a shortcut set up for voiceover and color inversion and I can zoom by double clicking the screen with three fingers. There is also a website called AppleVis that has reviews about how accessible each app is :)

I will try and make a case for an Android since I live somewhere where the terrible exchange rate makes an iPhone completely unaffordable. I use a Samsung Galaxy S5 which is pretty old. I do know that the newer ones have the same features though, so feel free to see what is available.

When I could still see a bit this phone was perfect. You can set a shortcut to triple tap home to invert colours and to triple tap the screen to zoom in in any app. What is also nice about the talkback on this phone is that it has an experimental one tap select mode, so if you can still see a bit and you just want it to read stuff you can still browse the screen and have it read everything back, but you don't have to learn all the new gestures and stuff to make it work. I started using talkback to its fullest last week, and most of the gestures required is bypassable by just using two fingers instead of one. Talkback works with only one finger, so if you use two it ignores talkback and just accesses the app/phone directly. That really comes in handy when you suck at double tapping and holding and then swiping to answer a call. :)

I was on a Droid 4 for a long time, since it's one of the last phones that had a slider keyboard. It eventually started giving up the ghost and was definitely slow, etc., so I finally upgraded last winter, and got the Moto Z Play Droid. (My other two desires were the LG V20 and the Pixel, but both were brand new and pretty expensive vs the Moto Z Play Droid being free.)

When I had the Droid 4, I had unlocked it and installed CyanogenMod with the dark material theme; between that and the build-in Android magnifier, it was enough. Since I can't unlock my Moto (thanks Verizon), I get by with the high contrast toggle on my notification drawer and magnifier. I have enough vision to get by with those options and one of the credit-card-size pocket magnifiers from Walmart if I need backup.

I've never been a fan of Apple (paying extra for their stuff to cover their marketing budget), but have heard their accessibility options are better than what Android offers. I also stay away from Samsung since they have a 'throw every gimmick at the new phones and see what sticks' mentality.

I'd suggest going to big-box electronics or carrier cellular stores and checking out the options directly.

I'm partially sighted from retinoblastoma and severely deaf, so any kind of talking software doesn't work for me. All my friends who rely on this use iphones and say they are the best.

Relying solely on xl/huge fonts, ability to change font style, as well as phone themes and colours and compatibility with these, I actually found android worked better for me. I couldn't see facebook on my iPhone 7 the writing was so small. Now I have an lg g6 and very pleased with it (would also recommend Samsung for their bright screens).

Hope that is helpful in some way. Have you thought about going into the phone shop and playing around with a few different models to see which might suit you best ?

I use iphones, and I find them very reliable when it comes to accessibility. It's true that there are more options with android, but I think most people would say the ios accessibility features are more dependable. I would think about giving the iPhone a try if I was you; you may be able to find some store that will let you buy an iphone and return it withint a set amount of time. If you feel as though android and the iphone do not meet your exact needs, there might be some nitch android app that would work for you that I don't know about.

Good luck