How does the Android App Ecosystem work?

[AC Question]

Hi there,

I recently read up about android and I'm quite puzzled how they do what they do.
From wikipedia, I understand that android runs on ARM as well as x86.

As a developer, would I only need to develop one app and that runs on all phones, tablets, android tvs etc? Both on ARM as well as x86? (similar to JAVA using bytecode?)
So they fully capsuled all hardware drivers, including graphics drivers? Is that still fast enough for 4k 3D?

And I'm even more puzzled by the driver model.
As a thought experiment, let's say that I developed an amazing new sensor that can e.g. check blood sugar (as far as I know, there isn't). Let's say Samsung developed this sensors and wants to bring it out in their Galaxy S9.
Can they write their own sensor hardware drivers that plug into Android? That would mean that the apps using that sensors are Samsung-specific, which I think doesn't work in the Android OHA. So do they need to push a standard sensor driver / API into Android first before shipping the new phone?

Or, if LG decides to bring out their own sensor, could there be two different kinds of sensors with different drivers/APIs, so that Samsung/LG apps using a sensor like that would not be compatible to each other?

I'm very curious about how that works and would appreciate any help.

Cheers,
Holger

PS: is there any good high-level introduction on how the android platform and app store ecosystem works?

 

[belodion]

Would you like me to move this to the Developers Lounge forum for further discussion with other members there?

 

[Holger Mayer]

belodion, Yes, would you please move it? For some reason I didn't think of posting it there in the first place, but it would fit better.

 

[belodion]

Moved.

 

[Rukbat]

Android pretty much is Java, it's just google's version of it. Apps contain hooks to Dalvik (Android's Java equivalent) APIs, so there's no need for a generic driver that app apps can use - they all use the API itself.

Is it fast enough for 4k? Evidently, since you can watch 4k videos on devices that support 4k. 4k 3D? I don't know - but I know that my older 3D TV never switches to 3D - there's never anything on. (I guessed wrong - I chose 3D rather than 4k, even though 4k was a bit cheaper at the time.)

Oh, and as far as a glucometer (blood sugar measure), look in the Play Store - many glucometers are Bluetooth-enabled, and can talk to their apps directly - you get a reading, it's recorded. So that part would be reinventing the wheel. (Or every manufacturer could put a glucometer strip port in their phones, then we'd have another dozen choices. I think there are enough already.