> But the essential point is that nobody can afford to ignore Android and building to iOS-specific APIs doesn't make sense.

For broad market maybe, but for niche markets a good example would be ForeFlight https://www.foreflight.com/products/foreflight-mobile/ It's pretty much the gold standard among pilots, from private to airline transport, and it's IOS only. Makes support and dealing with fragmentation a whole lot easier.

This is an almost silly point. How many less significant than this features hold companies hostage to Microsoft? So it's ok when Microsoft makes Microsoft/Windows only frameworks and software but not when Apple does it? Sheesh. Of course vendors are going to specialize their offerings.

Of course Apple and developers can choose to ignore Android.

The market within the iOS space is huge and if building an iOS only app using ARKit is more profitable then why not ? It's all about ROI. There isn't an equivalent for ARKit on Android and building one would be costly and time consuming.

There is, it's called project tango and they have had development devices for sale for a while (probably a year or so).

How large of a device marketshare could a developer count on at this point from Tango to justify investing heavily in that platform? One thing is for sure, developers can count on a significant share of paying customers if they go with ARKit.

ARToolKit isn't markerless like ARKit though.

There have been MP3 players for years. Apple is pretty late to the game.

There have been smartphones for years. Apple is pretty late to the game.

> But the essential point is that nobody can afford to ignore Android and building to iOS-specific APIs doesn't make sense

Surely you are referring to some future point in time, because most can still afford to ignore Android, use iOS-specific APIs, and be profitable.