Update README.md

Author: ps2

README.md

@@ -7,6 +7,8 @@
 
 Loop is an app template for building an artificial pancreas. It is a stone resting on the boulders of work done by [@bewest](https://github.com/bewest/decoding-carelink), [@ps2](https://github.com/ps2/rileylink) and many others.
 
+Loop is built on top of [LoopKit](https://github.com/LoopKit/LoopKit). LoopKit is a set of frameworks that provide data storage, retrieval, and calcluation, as well as boilerplate view controllers used in Loop.
+
 Please understand that this project:
 - Is highly experimental
 - Is not approved for therapy
@@ -66,13 +68,13 @@ Please understand that this project:
 <br/><a name="hw3">3</a>. Early firmware (US <= 2.4A, AU/EUR <= 2.6A) is required for using Closed Loop and Bolus features.
 <br/><a name="hw4">4</a>. It's not impossible, but comms-heavy and there's some work to be done. File an issue if you're someone who's up for the challenge and can test this hardware configuration.
 
-### RileyLink
+### Mac and XCode
 
-Bluetooth LE communication with Minimed pumps is enabled by the [RileyLink](https://github.com/ps2/rileylink), a compact BLE-to-916MHz bridge device designed by the incredible [@ps2](https://github.com/ps2). Please visit the [repository](https://github.com/ps2/rileylink) and the [gitter room](https://gitter.im/ps2/rileylink) for more information.
+To build Loop you will need a mac computer, and have Xcode 8 installed on it.  You will need to use git, either from the command line, or with a GUI like the Github Desktop Client.
 
-### LoopKit
+### RileyLink
 
-Loop is built on top of [LoopKit](https://github.com/LoopKit/LoopKit). LoopKit is a set of frameworks that provide data storage, retrieval, and calcluation, as well as boilerplate view controllers used in Loop.
+Bluetooth LE communication with Minimed pumps is enabled by the [RileyLink](https://github.com/ps2/rileylink), a compact BLE-to-916MHz bridge device designed by the incredible [@ps2](https://github.com/ps2). Please visit the [repository](https://github.com/ps2/rileylink) and the [gitter room](https://gitter.im/ps2/rileylink) for more information.
 
 # Getting Started