@wojtek Sounds are OK. I would select the last one but they are under CC license, so we would need to add info about source of the sound and link to that page. I'm not sure if we should do that? or just find sound on more permissive license?

Why wouldn't / shouldn't we do that? (I noticed that some apps just list those resources in "about" section).

What struck me is that the pattern itself is not licensed, only the file created based on the spec. So, it says 1s tone of 440Mhz (425Mhz) and then 3-5s of silence... Audacity, couple minutes of clicking and we have our own, awesome tone (1s of 441Mhz, 2s of silence).

I guess this is ok now? :-)

sound.ogg

We can add info to the "About" section, but I'm not convinced that we should do that and use that resources/libraries if we may have another (free) alternative.

Thank you for the generated sound. That will work just fine :)

Now, calling sound should appear.