Android Basics: How to Add Your Own Ringtones & Notification Sounds « Android :: Gadget Hacks
4 formas de hacer tu propio ringtone (timbre del celular)
How to Get the Classic Nexus Ringtones & System Sounds on Any Rooted Phone « Android :: Gadget Hacks
Old Phone Preservation on Twitter: "Sticking to the #Google Sooner topic, thanks to the aforementioned dump, the prototype's ringtones have been ripped and uploaded! https://t.co/WFuaB2Gaio (Replace HTTPS with HTTP if you click