Zapier is a third party connector that connects one or more softwares (including Delivra) to each other through API services.
In practice, Zapier acts as a trigger to action based service - a trigger in one app (Formstack, for example) can fire one or more changes to an action app (Delivra, for example). You can also have triggers fire changes at multiple apps (a new Formstack submission creates a lead at Salesforce and a contact in Delivra, for example).
To illustrate this, you can see that available triggers for Delivra are New Contacts or New Unsubs. This means when someone is added as a contact, it can trigger an action in another system, etc. On the flip side, our actions are to create or update contact records. Meaning, when a trigger happens in another system (like Formstack), it can create or update a contact in Delivra:
Zapier is useful because of its long reach - many top softwares connect with Zapier. Their App Store has over 1,000 apps and should be the first place you look when you get the question "Does Delivra integrate with..."
Some apps, like Delivra, can be accessed for free (though you must have a Delivra account). Other apps, like Salesforce or GoToMeeting are paid at a monthly rate (Premium apps).
Check out more about the basics of Zapier here.
You can find out more about Delivra's capabilities with Zapier here.
How-to guide on testing your Zaps here.