Alexa skills and AR / VR Apps

As of 2019 August, alexa and amazon developer rewards programs seem to be taking off a bit more than when launched.

Alexa:
Similar to iphone apps .. meditate and coaching tools are present

Lot of voice over apps obviously .. 

AR/VR is way more interesting!

https://jacksadvice.com/best-free-vr-apps-list/1282/

video games along the lines of sniper

consume video content, maps or earth applications, extending to space

and practically anything on the imagination space is what is there in the AR/VR.

There is relatively less paid apps or market in this medium. Again the usual suspects like Apple are on the front. And these guys or their marketing team will not get in unless there is a sizeable enough market participation or assets to develop. 

Summing up, if you are looking for paid version of the apps, go in the following order:

start with iOS and other Apple platforms

Then Alexa,

then other platforms like AR/VR slowly and feature wise

then android and other open source platforms.

Of course Linux and other truly open source technologies and platforms are different game altogether. Here in the enterprise market one can make money but forget about consumer platforms.