diff --git a/manifest.json b/manifest.json
index 5c52be5..468eb5f 100644
--- a/manifest.json
+++ b/manifest.json
@@ -14,7 +14,7 @@
         "email": ""
     },
     "requirements": {
-        "yunohost": ">= 4.0.0"
+        "yunohost": ">= 4.1.7"
     },
     "multi_instance": true,
     "services": [
@@ -25,34 +25,32 @@
             {
                 "name": "domain",
                 "type": "domain",
-                "ask": {
-                    "en": "Choose a domain for TiddlyWiki",
-                    "fr": "Choisissez un nom de domaine pour TiddlyWiki"
-                },
                 "example": "domain.org"
             },
             {
                 "name": "path",
                 "type": "path",
-                "ask": {
-                    "en": "Choose a path for TiddlyWiki",
-                    "fr": "Choisissez un chemin pour TiddlyWiki"
-                },
                 "example": "/tiddlywiki",
                 "default": "/tiddlywiki"
             },
             {
                 "name": "is_public",
                 "type": "boolean",
-                "ask": {
-                    "en": "Is it a public application?",
-                    "fr": "Est-ce une application publique ?"
-                },
                  "help": {
                         "en": "If enabled, TiddlyWiki will be accessible by people who doesn’t have an account. This can be changed later via the webadmin.",
                         "fr": "Si cette case est cochée, TiddlyWiki sera accessible aux personnes n’ayant pas de compte. Vous pourrez changer ceci plus tard via la webadmin."
                 },
                 "default": true
+            },
+            {
+                "name": "language",
+                "type": "string",
+                "ask": {
+                    "en": "Choose the application language",
+                    "fr": "Choisissez la langue de l'application"
+                },
+                "choices": ["fr", "en"],
+                "default": "fr"
             }
         ]
     }
diff --git a/scripts/change_url b/scripts/change_url
index e912667..6e8d89a 100644
--- a/scripts/change_url
+++ b/scripts/change_url
@@ -8,8 +8,6 @@
 
 source /usr/share/yunohost/helpers
 
-ynh_abort_if_errors
-
 #=================================================
 # RETRIEVE ARGUMENTS
 #=================================================
diff --git a/scripts/install b/scripts/install
index de02526..6d31eb5 100755
--- a/scripts/install
+++ b/scripts/install
@@ -22,6 +22,7 @@ ynh_abort_if_errors
 domain=$YNH_APP_ARG_DOMAIN
 path_url=$YNH_APP_ARG_PATH
 is_public=$YNH_APP_ARG_IS_PUBLIC
+language=$YNH_APP_ARG_LANGUAGE
 
 app=$YNH_APP_INSTANCE_NAME
 
@@ -42,8 +43,9 @@ ynh_webpath_register --app=$app --domain=$domain --path_url=$path_url
 #=================================================
 ynh_script_progression --message="Storing installation settings..." --weight=2
 
-ynh_app_setting_set --app=$app --key=domain    --value=$domain
-ynh_app_setting_set --app=$app --key=path      --value=$path_url
+ynh_app_setting_set --app=$app --key=domain   --value=$domain
+ynh_app_setting_set --app=$app --key=path     --value=$path_url
+ynh_app_setting_set --app=$app --key=language --value=$language
 
 #=================================================
 # STANDARD MODIFICATIONS
@@ -58,7 +60,12 @@ ynh_app_setting_set --app=$app --key=final_path --value=$final_path
 #ynh_setup_source --dest_dir="$final_path"
 
 mkdir -p $final_path
-cp -a ../sources/empty.html $final_path/empty.html
+
+if [ "$language" = "fr" ]; then
+	cp -a ../sources/empty_fr.html $final_path/empty.html
+else 
+	cp -a ../sources/empty.html $final_path/empty.html
+fi
 
 #=================================================
 # NGINX CONFIGURATION
diff --git a/scripts/upgrade b/scripts/upgrade
index 90cac05..b3fcb6e 100644
--- a/scripts/upgrade
+++ b/scripts/upgrade
@@ -18,6 +18,7 @@ app=$YNH_APP_INSTANCE_NAME
 domain=$(ynh_app_setting_get --app=$app --key=domain)
 path_url=$(ynh_app_setting_get --app=$app --key=path)
 final_path=$(ynh_app_setting_get --app=$app --key=final_path)
+language=$(ynh_app_setting_get --app=$app --key=language)
 
 #=================================================
 # CHECK VERSION
@@ -36,6 +37,19 @@ if [ -z "$final_path" ]; then
 	ynh_app_setting_set --app=$app --key=final_path --value=$final_path
 fi
 
+# Save the language used if not present
+if [ -z "$language" ]; then
+  language="en"
+  ynh_app_setting_set --app=$app --key=language --value=$language
+fi
+
+# Cleaning legacy permissions
+if ynh_legacy_permissions_exists; then
+	ynh_legacy_permissions_delete_all
+
+	ynh_app_setting_delete --app=$app --key=is_public
+fi
+
 #=================================================
 # BACKUP BEFORE UPGRADE THEN ACTIVE TRAP
 #=================================================
@@ -61,7 +75,12 @@ then
 	# Download, check integrity, uncompress and patch the source from app.src
 	#ynh_setup_source --dest_dir="$final_path"
 	mkdir -p $final_path
+	
+	if [ "$language" = "fr" ]; then
+	cp -a ../sources/empty_fr.html $final_path/empty.html
+	else 
 	cp -a ../sources/empty.html $final_path/empty.html
+	fi
 fi
 
 #=================================================