BlackBerry has long been pushing their UI Guidelines for BlackBerry 10 to add consistency for third party applications. They have just updated the guidelines for BlackBerry 10.2 and includes some nice additions. Thankfully they have added Earconography which explains how to design sounds for BlackBerry 10 by giving you a sample from the default BlackBerry 10 sounds. Personally I wish BlackBerry would include more differentiating sounds in BlackBerry 10 since notifications can be confusing.
My favorite new addition is BlackBerry adding Wireframe Prototypes for developers to mock up BlackBerry 10 UI designs. This helps you easily create templates for customers before coding anything. Last but not least they have added more documentation on dialog boxes and toasts for BlackBerry 10.