Just want to say one thing as why it's so costly to develop for ARM. ARM isn't really a single architecture. There are minor variations in instruction sets for different manufacturers. Which means a developer has to build separate binaries for each processor family and test seperately on each device. So you would need a separate binary for RPi, Chromebook, Beagleboard, etc...
This is why android apps are predominantly JAVA based. Running on a JVM means you don't need to worry about underlying architecture/instruction set differences.
Even opensouce projects restrict official support for ARM devices because of this.