[iOS app] Improve content (#499)

Closes #200 

* initial edits

Added detail to iOS app page, including feature list, screenshots, and
brief setup instructions

* Initial edits

Reference issue 200, added feature list, screenshots, and getting
started instructions.

* Updates per review

Fixed some grammar and formatting issues, provided more accurate
description of app’s remote capabilities, and fixed image width display.

Signed-off-by: Tom Nerison captomner@gmail.com (github: dome2048)

* Add a few corrections

Signed-off-by: Thomas Dietrich <thomas.dietrich@tu-ilmenau.de> (github: ThomDietrich)

addons/uis/apps/ios.md

@@ -10,12 +10,42 @@ title: iOS openHAB App
 <!-- https://developer.apple.com/app-store/marketing/guidelines/de/#downloadOnAppstore -->
 
 We provide a native iOS app for openHAB, compatible with iPhone and iPad.
-It uses the REST API of openHAB to render sitemaps of your openHAB installation.
+It uses the REST API of openHAB to render sitemaps of your openHAB installation for a natural iOS feeling.
-It also supports [myopenhab.org](http://www.myopenhab.org) including push notifications.
+
+## Features
+
+- View and control openHAB sitemaps
+- Connect to local openHAB instances on the local network
+- Connect to your openHAB instance remotely, either using a direct connection or via myopenHAB
+- Receive push notifications on your iOS devices via myopenHAB
+- Natively supports both iPhone and iPad
+
+<div class="row">
+  <div class="col s12 m4"><img src="images/ios01.png" alt="Demo Main Menu"></div>
+  <div class="col s12 m4"><img src="images/ios02.png" alt="Demo Widget Overview"></div>
+  <div class="col s12 m4"><img src="images/ios03.png" alt="Settings"></div>
+</div>
+
+## Installation and Setup
+
 The latest release version of the app is always available through the Apple App Store.
 
 [![Download openHAB app on the App Store](images/download-on-the-app-store.png)](https://itunes.apple.com/us/app/openhab/id492054521)
 
-Please refer to the [openhab.ios project](https://github.com/openhab/openhab.ios) on GitHub for more technical details.
+The app will start in Demo mode by default.
+A demo home automation setup is shown.
+This allows you to explore the possibilities of a typical openHAB installation.
 
-{% include contribution-wanted.html %}
+To view and control your own devices, navigate to the Settings page, then disable the "Demo mode" checkbox.
+In the "Local URL" field enter the base URL to your openHAB webinterface, either using its IP address (e.g. `http://192.168.1.125:8080`) or hostname (e.g. `http://openhabianpi:8080`).
+
+You can also connect to openHAB remotely, using either a direct connection or an openHAB Cloud instance like myopenHAB.
+Please see the [article on secure remote access](http://docs.openhab.org/installation/security.html) for more details.
+Simply enter your "Remote URL" in the respective Settings field.
+The openHAB app will henceforth first try connecting to the local URL, then fall back to the remote URL.
+
+## Help and Resources
+
+If your question or problem isn't covered here in the documentation pages, check the [openHAB Community Forum](https://community.openhab.org). 
+
+Also, please refer to the [openhab.ios project](https://github.com/openhab/openhab.ios) on GitHub for more technical details.