This extension can be used to send an email alert to Manufacturer to update them about the order of their item. And So they can process their orders.

Magento2 Extension Installation Service

This extension will provide feature to admin using which admin can add different numbers of white papers for the users of the site. User can download white paper by making a request. Request can be made by submitting the "Request form" extension have.

Product Attachments Magento Extension

This extension basically used to save custom options pricing using csv. It will work when you have 2 custom options.