We have replaced our SharePoint add-in with Microsoft's recommended integration approach which allows access to OneDrive and all SharePoint sites without the need to install anything.
For details, please refer to our article: Synchronize documents across SharePoint, OneDrive, DropBox and Google Drive
The SharePoint Add-in is specifically designed for use with SharePoint online.
If you have Office 365 and SharePoint online, you can download the add-in by clicking the button below:
If you use an on-premise installation of SharePoint, contact us regarding access to our enterprise version.
A lot of organizations lock down access to the SharePoint Add-in store. You may need to ask your SharePoint support staff to help you, just send them this link.
As always, don't hesitate to contact us is needed.