(1)This Extension make your Store to new way when product Not Available customer can add notify message So Customer can get mail.when product is available then customer get automatically mail with cron.
(2)You can Edit email Template Also From backend.
(3)For Any update or change in version pin me on sale.opencart@gmail.com.
(4)Use Filter at backend for product
(5) With IP Address
(6)You can Export that data Also.
(7)Other Version Can avilablle As per Requirement