[phire]

- It's significantly easier to monetize mobile apps (both with ads and in-app purchases)

- Open projects already dominate the desktop space

- There are a growing number of younger people who aren't really computer literate, or otherwise just use their phone as their primary computing device.

- Phones go into social situations where desktops/laptops don't.

[HPsquared]

Phones also have cameras built-in, which would fit well with img2img.