diff --git a/conf/.env b/conf/.env
index f8eb9ff..bf9a919 100644
--- a/conf/.env
+++ b/conf/.env
@@ -2,4 +2,5 @@ ME_CONFIG_SITE_BASEURL=__PATH__
 ME_CONFIG_BASICAUTH=false
 ME_CONFIG_BASICAUTH_USERNAME=
 ME_CONFIG_MONGODB_ENABLE_ADMIN=true
+ME_CONFIG_SITE_SESSIONSECRET=SomeSecret6533
 PORT=__PORT__
diff --git a/manifest.toml b/manifest.toml
index 87d42dc..3b1e971 100644
--- a/manifest.toml
+++ b/manifest.toml
@@ -39,7 +39,7 @@ ram.runtime = "50M"
 
     [install.init_main_permission]
     type = "group"
-    default = false
+    default = "visitors"
 
     [install.mongo_version]
     ask.en = "Select the major version of Mongo to install or 'None' if already installed"
diff --git a/scripts/_common.sh b/scripts/_common.sh
index b818f0f..334340f 100644
--- a/scripts/_common.sh
+++ b/scripts/_common.sh
@@ -13,6 +13,11 @@ nodejs_version=16
 #=================================================
 # EXPERIMENTAL HELPERS
 #=================================================
+_install_yarn () {
+    ynh_exec_as "$app" "$ynh_node_load_PATH" npm install yarn
+    ynh_yarn="$install_dir/node_modules/.bin/yarn"
+    alias ynh_yarn="$ynh_yarn"
+}
 
 #=================================================
 # FUTURE OFFICIAL HELPERS
diff --git a/scripts/install b/scripts/install
index 483cab4..2086fa5 100755
--- a/scripts/install
+++ b/scripts/install
@@ -13,10 +13,15 @@ source /usr/share/yunohost/helpers
 #=================================================
 # INSTALL DEPENDENCIES
 #=================================================
-ynh_script_progression --message="Installing NodeJS..." --weight=3
+ynh_script_progression --message="Installing NodeJS & Yarn..." --weight=3
 
 ynh_install_nodejs --nodejs_version="$nodejs_version"
 
+pushd "$install_dir"
+    ynh_use_nodejs
+    _install_yarn
+popd
+
 # Install mongo server only if asked to
 if [ "$mongo_version" != "None" ]; then
     ynh_script_progression --message="Installing MongoDB..." --weight=3
@@ -46,12 +51,13 @@ chown "$app:$app" "$install_dir/.env"
 #=================================================
 # BUILD NODEJS CODE
 #=================================================
-ynh_script_progression --message="Building NodeJS code and dependencies..." --weight=6
+ynh_script_progression --message="Building NodeJS code ..." --weight=6
 
-# Install Nodejs dependencies
+# Build using Yarn
 pushd "$install_dir"
     ynh_use_nodejs
-    ynh_exec_as "$app" "$ynh_node_load_PATH" "$ynh_npm" install
+    ynh_exec_as "$app" "$ynh_node_load_PATH" "$ynh_yarn" install
+    ynh_exec_as "$app" "$ynh_node_load_PATH" "$ynh_npm" run build
 popd
 
 #=================================================
diff --git a/scripts/upgrade b/scripts/upgrade
index d6d6637..64b53bf 100644
--- a/scripts/upgrade
+++ b/scripts/upgrade
@@ -22,10 +22,15 @@ ynh_systemd_action --service_name="$app" --action="stop" --log_path="/var/log/$a
 #=================================================
 # INSTALL DEPENDENCIES
 #=================================================
-ynh_script_progression --message="Installing NodeJS..." --weight=3
+ynh_script_progression --message="Installing NodeJS & Yarn" --weight=3
 
 ynh_install_nodejs --nodejs_version="$nodejs_version"
 
+pushd "$install_dir"
+    ynh_use_nodejs
+    _install_yarn
+popd
+
 # Install mongo server only if asked to
 if [ "$mongo_version" != "None" ]; then
     ynh_script_progression --message="Installing MongoDB..." --weight=3
@@ -57,10 +62,11 @@ chown "$app:$app" "$install_dir/.env"
 #=================================================
 ynh_script_progression --message="Building NodeJS code and dependencies..." --weight=6
 
-# Install Nodejs dependencies
+# Build using Yarn
 pushd "$install_dir"
     ynh_use_nodejs
-    ynh_exec_as "$app" "$ynh_node_load_PATH" "$ynh_npm" install
+    ynh_exec_as "$app" "$ynh_node_load_PATH" "$ynh_yarn" install
+    ynh_exec_as "$app" "$ynh_node_load_PATH" "$ynh_npm" run build
 popd
 
 #=================================================
diff --git a/scripts/ynh_mongo_db__2 b/scripts/ynh_mongo_db__2
index e1c17a6..cb7317b 100644
--- a/scripts/ynh_mongo_db__2
+++ b/scripts/ynh_mongo_db__2
@@ -314,17 +314,19 @@ ynh_install_mongo() {
 
 	ynh_print_info --message="Installing MongoDB Community Edition ..."
 	local mongo_debian_release=$(ynh_get_debian_release)
+  local mongo_packages="mongodb-org-server mongodb-database-tools mongodb-org-shell"
 
 	if [[ $(cat /proc/cpuinfo) != *"avx"* && "$mongo_version" != "4.4" ]]; then
     ynh_print_warn --message="Installing Mongo 4.4 as $mongo_version is not compatible with your cpu (see https://docs.mongodb.com/manual/administration/production-notes/#x86_64)."
     mongo_version="4.4"
   fi
-  if [[ "$mongo_version" == "4.4" && "$mongo_debian_release" != "buster" ]]; then
-    ynh_print_warn --message="Switched to buster install as Mongo 4.4 is not compatible with $mongo_debian_release."
+  if [[ "$mongo_version" == "4.4" ]]; then
+    ynh_print_warn --message="Switching to buster package install for Mongo 4.4."
     mongo_debian_release=buster
+    mongo_packages="mongodb-org-server mongodb-database-tools mongodb-mongosh-shared-openssl11"
   fi
 
-	ynh_install_extra_app_dependencies --repo="deb http://repo.mongodb.org/apt/debian $mongo_debian_release/mongodb-org/$mongo_version main" --package="mongodb-org mongodb-org-server mongodb-org-tools mongodb-mongosh" --key="https://www.mongodb.org/static/pgp/server-$mongo_version.asc"
+	ynh_install_extra_app_dependencies --repo="deb http://repo.mongodb.org/apt/debian $mongo_debian_release/mongodb-org/$mongo_version main" --package="$mongo_packages" --key="https://www.mongodb.org/static/pgp/server-$mongo_version.asc"
 	mongodb_servicename=mongod
 
 	# Make sure MongoDB is started and enabled