A block-based framework for building Bluetooth 4.0 Low Energy (aka Smart or LE) iOS 7 or OS X 10.9 applications using the CoreBluetooth API. Includes Deanna and DeannaMac, applications to communicate with a TI SensorTag for iOS and OS X respectively. Transactions in Bluetooth LE (BLE) are two-phase (request-response) in nature: CoreBluetooth abstracts this protocol so that request behavior is separated from response behavior. The two phases are reconciled using a delegation pattern: the object initiating the request phase has a delegate object with a delegate method to handle the corresponding response phase. While functional, the delegation pattern can be cumbersome to use because the behavior for a two-phase transaction is split into two different locations in code.