Besides all the errands of a smartwatch, the Pebble can pull most common push notifications off an iPhone's stock iOS apps, such as new texts, e-mails, caller ID, and appointments (calendar), but lacked a means to pull notifications off third-party apps such as Twitter, Google+, Facebook, etc. This is either because Apple restricts low-level communications between apps, or it didn't approve of Pebble's app that grabs those notifications. Its developers came up with an alternate at-you-own-risk method for those who absolutely, positively need third-party app notifications on their Pebble.
Pebble developer Conrad Kramer innovated a new tweak "BTNotificationEnabler," which is posted on Cydia, where jailbroken iOS devices go for a wealth of third-party software not found on the App Store. The tweak redirects every single entry to the iPhone's Notification Center drawer to Pebble over Bluetooth, and so you could read Tweets, Facebook notifications, and more.
The onus is now on Pebble loyalists if they want to go ahead and jailbreak their iPhones against Apple's wishes and rhetoric. It will also be interesting to see how Apple responds to one of its App developers abetting jailbreaks.