Before You Begin
Make sure that you have Removed the Add-In from Site Collection Recycle Bin
Step 1: Login to your Office 365 admin center page with administrator account, then choose Admin
Go to SharePoint Admin Center
Or in the new admin center
Step 3: Select Apps then Click on App Catalog
Step 4: Open Apps for SharePoint
Find ShortPoint item and right-click to open the context menu and click Delete.