Fun fact: the creator of these tones is Hugo Verweij. You may recognize his name if you read The New Yorker's piece on Jony Ive. Hugo has since joined Jony's design team. Can't recommend them enough. They're very well done.
I keep my phone on silent almost all the time as to not bother anyone else. However, sometimes you need to turn on the ringer for one reason or another and I've gotten super annoyed with the standard ringtones that come on the device.
I've gone through a # of custom ringtones to try and find something I like but the quality is usually low... These sounds are like there's some tiny little gnome in my ear with some awesome little gnome instrument that gently massages my eardrums when my phone has something to tell me. Makes me smile.
Also, you can pay with a tweet!
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