I don't mind the source "leaking", as stated in the article. I'm even planning to just send it onto paying customers, but that's impossible on mobile platforms without making it public. I want a hurdle, just enough to make people consider buying instead of downloading. Take Fritzing for example, for os X and windows you must pay for an installer or compile yourself, on most Linux distros it's an apt insta away.

I've had multiple forms of donation buttons on my various sites and software over the years and they have never worked as good as either ads or paid software. As in, 99% difference.