A demo app for talking to a Bluetooth 4.0 device, specifically the Bluno Beetle (http://www.dfrobot.com/index.php?route=product/product&product_id=1259)
The tutorial for this demo app can be found here (https://medium.com/@rickredsix/getting-started-with-ios-swift-and-bluetooth-4-0-for-wearables-hardware-4661b1992bca)