Add screenshots, captures. Refs #90.

This commit adds several images and gifs to the README, to document examples of
how Keera Hails can be used. Images contain iOS, Android, Web and desktop
applications, to showcase Keera Hails' multiplatform features.

README.md

@@ -13,6 +13,87 @@ Webcams, etc).
 Keera Hails has been used to create large applications and is used commercially
 in production.
 
+# At a glance
+
+<table>
+  <tr>
+    <td>
+    <p align="center">
+      Keera Studios' Gale Studio!
+      <br /><br />
+      <a href="http://keera.co.uk" target="_blank">
+        <img src="https://keera.co.uk/wp-content/uploads/2011/10/Screenshot.png" height="auto" alt="Gale Studio screenshot" style="max-height:175px;"></a>
+      <img width="441" height="1">
+      <br />
+    </p>
+    </td>
+    <td>
+    <p align="center">
+      Guerric Chupin's Arpeggigon
+      <br /><br />
+      <a href="https://gitlab.com/chupin/arpeggigon" target="_blank">
+        <img src="https://keera.co.uk/wp-content/uploads/2020/05/arpeggigon.png" height="auto" alt="Arpeggigon screenshot" style="max-height:175px;"></a>
+      <img width="441" height="1">
+      <br />
+    </p>
+    </td>
+    <td>
+    <p align="center">
+      SoOSim simulator
+      <br />
+      <br />
+      <img src="https://keera.co.uk/wp-content/uploads/2011/10/Screenshot-from-2014-09-24-142046.png" height="auto" alt="CAES group's SoOSim" style="max-height: 175px;">
+      <img width="441" height="1">
+      <br />
+    </p>
+    </td>
+    </tr>
+  <tr>
+    <td>
+    <p align="center">
+      iOS demo
+      <br /><br />
+      <a href="http://keera.co.uk" target="_blank">
+        <img src="https://keera.co.uk/wp-content/uploads/2022/04/keera-hails-ios-demo-capture.gif" height="auto" alt="Keera Hails iOS demo app screenshot" style="max-height:175px;"></a>
+      <img width="441" height="1">
+      <br />
+    </p>
+    </td>
+    <td>
+    <p align="center">
+      Android demo
+      <br /><br />
+      <a href="http://keera.co.uk" target="_blank">
+        <img src="https://keera.co.uk/wp-content/uploads/2022/04/keera-hails-android-demo-capture.gif" height="auto" alt="Keera Hails Android demo app screenshot" style="max-height:175px;"></a>
+      <img width="441" height="1">
+      <br />
+    </p>
+    </td>
+    <td>
+    <p align="center">
+      Web demo
+      <br />
+      <br />
+      <a href="http://keera.co.uk" target="_blank">
+      <img src="https://keera.co.uk/wp-content/uploads/2022/04/hello-hails-web-calculator-css-final-orig-midres-short.gif" height="auto" alt="Keera Hails web demo app capture" style="max-height: 175px;"></a>
+      <img width="441" height="1">
+      <br />
+    </p>
+    </td>
+    </tr>
+    <tr>
+    <td colspan="3">
+      <sub>
+        <sup>
+	  Image from Gale Studio and Keera Hails demos are Copyright © 2011 -
+	  2022 Keera Studios Ltd. All Rights Reserved. Keera, Keera Studios,
+          Keera Hails, Gale, Gale Studio are trademarks of Keera Studios Ltd.
+        </sup>
+      </sub>
+    </td>
+  </tr>
+</table>
+
 # Hands-on example
 
 The two key ideas in Keera Hails are *Reactive Values* and *Reactive Rules*.
@@ -159,6 +240,24 @@ core ideas and problems that remain to be solved.)
 * [TFP 2014 Pre-proceedings, pages 59-68](http://www.staff.science.uu.nl/~hage0101/preproceedingstfp2014.pdf)
 * [Reactive Programming using Reactive Values (blog post)](http://keera.co.uk/blog/2014/05/24/reactive-programming-using-reactive-values/)
 
+
+<table>
+  <tr>
+    <td>
+    <p align="center">
+      Building a reactive calculator in Haskell!
+      <br /><br />
+      <a href="https://keera.co.uk/2020/05/28/building-a-reactive-calculator-in-haskell-1-5/" target="_blank">
+        <img src="https://keera.co.uk/wp-content/uploads/2022/04/hello-hails-web-calculator-css-final-orig-midres-short.gif" height="auto" alt="Keera Hails web demo app capture" style="max-height:175px;"></a>
+      <img width="441" height="1">
+      <br />
+      <sup>Copyright © 2020 - 2021 Keera Studios Ltd. All Rights Reserved.</sup>
+      <br />
+    </p>
+    </td>
+  </tr>
+</table>
+
 For bibtex references to these articles, see Publications in http://www.cs.nott.ac.uk/~ixp/.
 
 ## Applications and demos