diff --git a/scripts/backup b/scripts/backup
index 14f0869..334b8eb 100644
--- a/scripts/backup
+++ b/scripts/backup
@@ -39,12 +39,6 @@ ynh_backup --src_path=$final_path
 
 ynh_backup --src_path="/etc/nginx/conf.d/$domain.d/$app.conf"
 
-#=================================================
-# BACKUP LOGROTATE
-#=================================================
-
-ynh_backup --src_path="/etc/logrotate.d/$app"
-
 #=================================================
 # BACKUP SYSTEMD
 #=================================================
diff --git a/scripts/change_url b/scripts/change_url
index d92c78a..85f3330 100644
--- a/scripts/change_url
+++ b/scripts/change_url
@@ -104,4 +104,4 @@ ynh_systemd_action --service_name=nginx --action=reload
 # END OF SCRIPT
 #=================================================
 
-ynh_script_progression --message="Change of URL completed for $app" --last
+ynh_script_progression --message="Change of URL completed for $app"
diff --git a/scripts/install b/scripts/install
index 96e9cc6..1a2c929 100644
--- a/scripts/install
+++ b/scripts/install
@@ -110,8 +110,9 @@ ynh_script_progression --message="Installing The Lounge..."
 
 pushd $final_path
 
-yarn install && ynh_exec_warn_less NODE_ENV=production yarn build
-
+	ynh_use_nodejs
+	yarn install && ynh_exec_warn_less NODE_ENV=production yarn build
+	
 popd
 
 #=================================================
@@ -154,14 +155,6 @@ yunohost service add $app --description "Self-hosted web IRC client" --log "/var
 chown -R $app: $final_path
 chown -R $app: $config_path
 
-#=================================================
-# SETUP LOGROTATE
-#=================================================
-ynh_script_progression --message="Configuring log rotation..."
-
-# Use logrotate to manage application logfile(s)
-ynh_use_logrotate
-
 #=================================================
 # START SYSTEMD SERVICE
 #=================================================
@@ -189,4 +182,4 @@ ynh_systemd_action --service_name=nginx --action=reload
 # END OF SCRIPT
 #=================================================
 
-ynh_script_progression --message="Installation of $app completed" --last
+ynh_script_progression --message="Installation of $app completed"
diff --git a/scripts/remove b/scripts/remove
index 1b25793..2ac341f 100644
--- a/scripts/remove
+++ b/scripts/remove
@@ -68,14 +68,6 @@ ynh_script_progression --message="Removing nginx web server configuration..."
 # Remove the dedicated nginx config
 ynh_remove_nginx_config
 
-#=================================================
-# REMOVE LOGROTATE CONFIGURATION
-#=================================================
-ynh_script_progression --message="Removing logrotate configuration..."
-
-# Remove the app-specific logrotate config
-ynh_remove_logrotate
-
 #=================================================
 # GENERIC FINALIZATION
 #=================================================
@@ -90,4 +82,4 @@ ynh_system_user_delete --username=$app
 # END OF SCRIPT
 #=================================================
 
-ynh_script_progression --message="Removal of $app completed" --last
+ynh_script_progression --message="Removal of $app completed"
diff --git a/scripts/restore b/scripts/restore
index 720a610..e4b8c4e 100644
--- a/scripts/restore
+++ b/scripts/restore
@@ -115,12 +115,6 @@ ynh_script_progression --message="Starting a systemd service..."
 
 ynh_systemd_action --service_name=$app --action="start" --log_path="systemd" --line_match="Available at http"
 
-#=================================================
-# RESTORE THE LOGROTATE CONFIGURATION
-#=================================================
-
-ynh_restore_file --origin_path="/etc/logrotate.d/$app"
-
 #=================================================
 # GENERIC FINALIZATION
 #=================================================
@@ -134,4 +128,4 @@ ynh_systemd_action --service_name=nginx --action=reload
 # END OF SCRIPT
 #=================================================
 
-ynh_script_progression --message="Restoration completed for $app" --last
+ynh_script_progression --message="Restoration completed for $app"
diff --git a/scripts/upgrade b/scripts/upgrade
index abaf462..dd76818 100644
--- a/scripts/upgrade
+++ b/scripts/upgrade
@@ -100,6 +100,17 @@ then
 	ynh_setup_source --dest_dir=$final_path
 fi
 
+#=================================================
+# STORE THE CONFIG FILE CHECKSUM
+#=================================================
+
+### Verify the checksum of a file, stored by `ynh_store_file_checksum` in the install script.
+### And create a backup of this file if the checksum is different. So the file will be backed up if the admin had modified it.
+ynh_backup_if_checksum_is_different --file="$config_path/config.js"
+
+# Recalculate and store the checksum of the file for the next upgrade.
+ynh_store_file_checksum --file="$config_path/config.js"
+
 #=================================================
 # COPY A CONFIG FILE
 #=================================================
@@ -127,7 +138,8 @@ ynh_install_extra_app_dependencies --repo="deb https://dl.yarnpkg.com/debian/ st
 if [ "$upgrade_type" == "UPGRADE_APP" ]
 then
 	pushd $final_path
-
+	
+	ynh_use_nodejs
 	yarn install && ynh_exec_warn_less NODE_ENV=production yarn build
 
 	popd
@@ -176,14 +188,6 @@ ynh_store_file_checksum --file="$config_path/config.js"
 
 cp -a ../conf/config.js "$config_path"
 
-#=================================================
-# SETUP LOGROTATE
-#=================================================
-ynh_script_progression --message="Upgrading logrotate configuration..."
-
-# Use logrotate to manage app-specific logfile(s)
-ynh_use_logrotate --non-append
-
 #=================================================
 # GENERIC FINALIZATION
 #=================================================
@@ -194,6 +198,18 @@ ynh_use_logrotate --non-append
 chown -R $app: $final_path
 chown -R $app: $config_path
 
+#=================================================
+# SETUP SSOWAT
+#=================================================
+ynh_script_progression --message="Upgrading SSOwat configuration..." --time --weight=1
+
+# Make app public if necessary
+if [ $is_public -eq 1 ]
+then
+	# unprotected_uris allows SSO credentials to be passed anyway
+	ynh_app_setting_set --app=$app --key=unprotected_uris --value="/"
+fi
+
 #=================================================
 # START SYSTEMD SERVICE
 #=================================================
@@ -212,4 +228,4 @@ ynh_systemd_action --service_name=nginx --action=reload
 # END OF SCRIPT
 #=================================================
 
-ynh_script_progression --message="Upgrade of $app completed" --last
+ynh_script_progression --message="Upgrade of $app completed"