What are some alternatives?
When comparing ADrive and Skydrive, you can also consider the following products
AWS Storage Gateway - AWS Storage Gateway is a service connecting an on-premises software appliance with cloud-based storage.
Box - Box offers secure content management and collaboration for individuals, teams and businesses, enabling secure file sharing and access to your files online.
Azure Storage Explorer - Easily manage your Azure storage accounts in the cloud, from Windows, macOS, or Linux, using Azure Storage Explorer.
SugarSync - SugarSync is a cloud file sharing, file sync and online backup service that is simple, powerful and easy to use. Get a 30 day free trial!
VMware vSAN - VMware vSAN is radically simple, enterprise-class software-defined storage powering VMware hyper-converged infrastructure.
Dropbox - Online Sync and File Sharing