title: Unique identifier for peripheral BLE device
body: <p>So I have peripheral <code>BLE</code> device and I need some identifier for it to later share with another iPhone. Example I connect with <code>iPhone</code> 'A' to peripheral. <code>iPhone</code> 'A' saves peripheral's identifier to database and later I easily can take <code>iPhone</code> 'B' and connect to the peripheral found by this identifier. </p>
  
  <p>Now there is <code>UUID</code> what changes for every <code>iPhone-peripheral</code> connection, but <code>MAC 
  Address</code> is not available. What could you suggest? </p>