diff --git a/legacy_app_ynh/scripts/backup b/legacy_app_ynh/scripts/backup
index 9d0a803..8adc9de 100644
--- a/legacy_app_ynh/scripts/backup
+++ b/legacy_app_ynh/scripts/backup
@@ -7,9 +7,9 @@ source /usr/share/yunohost/helpers
 # Retrieve parameters
 
 # Backup directory (location dedicated to the app)
-backup_dir=$1
+backup_dir=.
 # App instance name
-app=$2
+app=$YNH_APP_INSTANCE_NAME
 domain=$(ynh_app_setting_get $app domain)
 
 # Copy the app files (explicitly specifying the backup dir)
diff --git a/legacy_app_ynh/scripts/install b/legacy_app_ynh/scripts/install
index d76ef82..9c92322 100644
--- a/legacy_app_ynh/scripts/install
+++ b/legacy_app_ynh/scripts/install
@@ -1,5 +1,8 @@
 set -eux
 
+# Source app helpers
+source /usr/share/yunohost/helpers
+
 # Retrieve arguments
 app=$YNH_APP_INSTANCE_NAME
 number=$YNH_APP_INSTANCE_NUMBER
@@ -8,7 +11,7 @@ path=$YNH_APP_ARG_PATH
 is_public=$YNH_APP_ARG_IS_PUBLIC
 
 # Check domain/path availability
-sudo yunohost app checkurl $domain/$path -a $app
+ynh_webpath_register --app=$app --domain=$domain --path_url=$path
 
 # Check folder availability
 test ! -e "/var/www/$app/"
@@ -22,8 +25,7 @@ sudo cp ../conf/nginx.conf /etc/nginx/conf.d/$domain.d/$app.conf
 sudo mkdir /var/www/$app
 sudo cp ../conf/index.html /var/www/$app
 
-sudo yunohost app checkport 12345
-if [[ ! $? -eq 0 ]]; then
+if ! ynh_port_available 12345; then
    echo "Ogod noez the port 12345 aint available!!"
    exit 1
 fi
@@ -31,8 +33,7 @@ fi
 # Create a dummy mysql db
 db_user=$app
 db_pwd="yoloswag42"
-sudo yunohost app initdb "$db_user" -p $db_pwd
-sudo yunohost app setting $app mysqlpwd -v $db_pwd
+ynh_mysql_setup_db --db_user=$db_user --db_name=$db_user --db_pwd=$db_pwd
 
 # Other custom stuff
 sudo cp ../sources/importantfile /etc/
diff --git a/legacy_app_ynh/scripts/restore b/legacy_app_ynh/scripts/restore
index 953f0a0..be8b617 100644
--- a/legacy_app_ynh/scripts/restore
+++ b/legacy_app_ynh/scripts/restore
@@ -1,8 +1,11 @@
 # No set -eu for this particular app restore script (see comment near the end)
 #set -eu
 
-restore_dir=$1
-app=$2
+# Source app helpers
+source /usr/share/yunohost/helpers
+
+restore_dir=.
+app=$YNH_APP_INSTANCE_NAME
 
 # Get old parameter of the app
 domain=$(sudo yunohost app setting $app domain)
@@ -18,8 +21,7 @@ sudo cp -a "${restore_dir}/conf/nginx.conf" $nginx_conf
 # Restore custom file
 sudo cp -a "${restore_dir}/importantfile" /etc/importantfile
 
-sudo yunohost app checkport 12345
-if [[ ! $? -eq 0 ]]; then
+if ! ynh_port_available 12345; then
    echo "Ogod noez the port 12345 aint available!!"
    exit 1
 fi
@@ -27,8 +29,9 @@ fi
 # Restore the database 
 db_user=$app
 db_pwd=$(sudo yunohost app setting $app mysqlpwd)
-sudo yunohost app initdb $db_user -p $db_pwd
-sudo su -c "mysql -u $db_user -p$db_pwd $app < ${restore_dir}/db.sql"
+ynh_mysql_setup_db --db_user=$db_user --db_name=$db_user --db_pwd=$db_pwd
+ynh_mysql_connect_as --user=$db_user --password=$db_user --database=$db_name < ${restore_dir}/db.sql
+
 # Some scripts wanted to delete the db.sql... This won't make the script crash
 # even if restore_dir is in read-only as long as there's no set -eu activated...
 sudo rm ${restore_dir}/db.sql