All data from Covve that can be synced back to your phone is. For example, if Covve finds the company and job title for someone, and you approve this update to be added to your contact then this info will be synced back to your phone. Two points here:
If you’re making changes on the webapp (app.covve.com from your desktop or laptop) then you do need to open the Covve app on your phone and let it sync up. Once it finishes you’ll see the updates in your phone.
While Covve syncs all possible pieces of data with your phone, there are a couple that are not possible to sync. For example “Industry” and “Seniority” do not exist on the iPhone/Android phones while social profiles and images are not possible due to technical issues.
In general, Covve will synchronize with your address book every few seconds while you're on-line.