PieSync is a 2-way integration tool.
It means that every time you create or update a contact in Overloop, it gets synced with all the other services your account is connected with through PieSync. And vice-versa.
NB: You will need to create a PieSync account in order to start using the service.
This is a sample of the apps you can connect to Overloop. Select them on the page or look for them in the search bar.
Once you've found the apps you'd like to connect, authorize both and let the magic happen!