diff --git a/app-config/docker-compose.yml b/app-config/docker-compose.yml
index 675b6829..917660ea 100644
--- a/app-config/docker-compose.yml
+++ b/app-config/docker-compose.yml
@@ -2,8 +2,6 @@ version: "3.8"
 services:
   cara-app:
     image: cara-voila-app
-    #        ports:
-    #    - "8080:8081"
     links:
       - cara-router
   cara-router:
diff --git a/app-config/nginx/404.html b/app-config/nginx/404.html
new file mode 100644
index 00000000..2000eebc
--- /dev/null
+++ b/app-config/nginx/404.html
@@ -0,0 +1 @@
+Page not found!
diff --git a/app-config/nginx/calculator-static b/app-config/nginx/calculator-static
new file mode 120000
index 00000000..5605de12
--- /dev/null
+++ b/app-config/nginx/calculator-static
@@ -0,0 +1 @@
+../../cara/apps/calculator/static
\ No newline at end of file
diff --git a/app-config/nginx/nginx.conf b/app-config/nginx/nginx.conf
index 660f5616..b32341d5 100644
--- a/app-config/nginx/nginx.conf
+++ b/app-config/nginx/nginx.conf
@@ -46,6 +46,8 @@ http {
         }
 
         location /voila-server/ {
+                # cara-app is the name of the voila server in each of docker-compose,
+                # test-cara.web.cern.ch and cara.web.cern.ch.
                 proxy_pass http://cara-app:8080/voila-server/;
 
                 proxy_set_header Host $host;
@@ -58,6 +60,12 @@ http {
                 proxy_read_timeout 86400;
         }
         rewrite ^/expert-app$ /voila-server/voila/render/cara.ipynb last;
+
+        # Give the static content of the calculator app a sensible name which is
+        # consistent with the static directory of the calculator webserver used
+        # for development.
+        rewrite ^/calculator/static/(.*)$ /calculator-static/$1 last;
+
         # Before implementing the nginx router we could access /voila/render/cara.ipynb.
         # Redirect this (and all other) URLs to the new scheme.
         rewrite ^/voila/(.*)$ /voila-server/voila/$1 redirect;
diff --git a/cara/apps/__init__.py b/cara/apps/__init__.py
new file mode 100644
index 00000000..da903ca1
--- /dev/null
+++ b/cara/apps/__init__.py
@@ -0,0 +1,4 @@
+from .expert import ExpertApplication
+
+
+__all__ = ['ExpertApplication']
diff --git a/cara/apps/calculator/__init__.py b/cara/apps/calculator/__init__.py
new file mode 100644
index 00000000..e69de29b
diff --git a/cara/apps/calculator/static/form.html b/cara/apps/calculator/static/form.html
new file mode 100644
index 00000000..e69de29b
diff --git a/cara/apps.py b/cara/apps/expert.py
similarity index 100%
rename from cara/apps.py
rename to cara/apps/expert.py