In a community forum post, Microsoft stated:
Delve helps you stay in the know, powered by who you know and what they are working on. With this preview app for Windows 10, you'll be notified about document updates, and get document suggestions that are relevant to your work. You can also find people and get back to your recent documents and attachments, all in one place – all in one app. In Delve, you can only see content that you already have permission to access. This means your colleagues won't see your private documents, and you won't see theirs.
The preview app is only available for Office 365 school or business subscribers with Office Delve access. A version for Windows 10 Mobile is in the works.