Google is now allowing third-party developers to integrate directly into Gmail with add-ons. Unlike the sort of Gmail utilities you may have used before (like Boomerang or Rapportive), add-ons will work directly in Gmail instead of through a Chrome extension. That will mean that they can work across Gmail on the web, in Android, and on iOS.

Google is launching this primarily as an enterprise feature for now. It’s working with Intuit, Salesforce, and Prosperworks already — so, for example, users will be able to create an invoice directly in Gmail and send it off in a reply. Google says the add-ons will be “contextual,” meaning they will only show up based on the content of the email you’re replying to.

But before you start agitating to get your favorite snoozing add-on developed directly into Gmail, remember that the primary focus here are enterprise customers. Google tells me that it won’t be an open marketplace to start, either — companies will need to parter with Google in order to get add-ons into Gmail.