If you are using Salesflare as a customer and have agreed to our Terms of Service, you do not need to sign an additional Data Protection Agreement. As of May 25th 2018, our user Terms of Service include a provision to ensure compliance with GDPR.
If you are a partner or a customer who needs to further document compliance with Salesflare acting as a Processor (for example, as a customer who processes their own users' data through Salesflare or as a partner who integrates directly with Salesflare) you can request a DPA for signature via this link.
You can find a sample of the DPA here.