added an image of Facebook embedded browser in iPhone iOS7

we should probably be looking as adding iPhone stylesheets, but…

frontend/templates/download.html

@@ -179,7 +179,8 @@ $j(document).ready(function() {
             </p>
             <p>
                 {% if formats.epub or formats.mobi %}
-                    To read this ebook you should open this page in safari, or use one of the "One-click" buttons, above. <br /><img width="500" height="403" src="/static/images/open_safari.png" alt="how to open in safari" /><br clear="left" />
+                    To read this ebook you should open this page in safari, or use one of the "One-click" buttons, above. <br />
+                    {% if iphone %}<img width="357" height="156" src="/static/images/clickhere.png" alt="how to open in safari" />{% else %}<img width="500" height="403" src="/static/images/open_safari.png" alt="how to open in safari" />{% endif %}<br clear="left" />
                 {% endif %}
                 {% if formats.pdf %}
                     You should also be able to use the  <a href="{{ formats.pdf }}">pdf</a> file.

frontend/views.py

@@ -2697,6 +2697,7 @@ class DownloadView(PurchaseView):
             'base_url': settings.BASE_URL_SECURE,
             'iOS': iOS,
             'iOS_app': iOS_app,
+            'iphone': 'iPhone' in agent,
             'android': android,
             'desktop': desktop,
             'mac_ibooks': 'Mac OS X 10.9' in agent or 'Mac OS X 10_9' in agent,