Sometimes, users will get a notification from Salestrail saying "Found and integrated x unlogged/logged calls".
This means the background handler (or so-called retro-sync) has detected some calls that haven't been logged or shown in Unlogged Activities, which happens because of:
Unstable internet connection / No internet connection.
Heavy call activities.
When the device has a good internet connection, it will likely let the retro-sync run and log / detect phone calls that Salestrail missed. The background handler runs randomly with no fixed schedule and frequency.
In conclusion, this notification lets you know that there were x calls that Salestrail missed at some points, but now, they've been logged (if Salestrail can find a match) or brought to Unlogged Activities (if Salestrail cannot find a match).