When you log into Spiro via Salesforce, Spiro syncs with Opportunities that you own that are still in an open stage. Spiro uses the out of box Opportunity Owner field to figure this out. Spiro will sync with the out of box Opportunity Name, Amount, Stage, Closed Date, Probability, Description and Forecast Category.
Spiro will sync with Contacts at Accounts that are associated with Opportunities you own. Opportunity Contacts will automatically be synced as "Key Contacts" in Spiro, while the rest of the Account Contacts will live in the "Other Contacts" list when looking at an Opportunity.
If you are exchanging emails or calendar events with someone whose email matches a contact's email address, Spiro will also automatically sync that person as a key contact as well.
Spiro will sync with the Contact Name, Title, Email, Phone and Mobile fields from Salesforce.
Spiro will show you the Account name of Accounts that are associated to Opportunities you own. However, integration with the Account object is limited and Spiro only shows the Account name as a reference point.
Spiro will sync with activities logged against Contacts that it tags as "Key Contacts". This is usually shown in the "Last Interaction" section of a recommendation card.
When someone makes a call from Spiro or logs an activity, Spiro automatically creates a completed activity for you. Spiro associates the activity with the Opportunity and Contact, while also automatically filling in the Status, Subject, and Description fields for you.
Spiro acts on your behalf as client to Salesforce. This means that Spiro has the same permissions that you would normally have, and using Spiro does not mean you have a work around to get to data that you normally would not be able to see.
As a certified ISV partner of Salesforce, Spiro has undergone rigorous security testing and has been personally vetted by a Salesforce Security Audit and placed on their whitelist program. Details of that can be found here.