pluralized it:P

at.py

@@ -20,6 +20,8 @@ import config
 app = Flask('at')
 app.wsgi_app = ProxyFix(app.wsgi_app)
 app.secret_key = config.secret_key
+app.jinja_env.add_extension('jinja2.ext.i18n')
+app.jinja_env.install_null_translations()
 updater = None
 
 from functools import wraps

templates/main.html

@@ -16,7 +16,11 @@ Now at hackerspace
     </li>
   {% endfor %}
   </ul>
+  {% trans n_unk=unknown|length %}
+  There is {{ n_unk }} unknown device operating. 
+  {% pluralize %}
+  There are {{ n_unk }} unknown devices operating. 
+  {% endtrans %}
   <hr>
-  There are {{ unknown|length }} unknown devices operating. 
   <a href="claim">Claim this device!</a>
 {% endblock %}