Sync can be somewhat tricky but done right, it's a great contact management/productivity gain. Our one major piece of advice is to choose one kind of sync (google sync, icloud, or zapier etc.) and stick with that, thus avoiding what we call "loops".
Here's how you can easily sync your mobile with your Evercontact contacts. And if the contacts on your phone (especially your iphone) are a mess, here's our advice on how to clean up those contacts. Evercontact can also sync to salesforce, highrise, connectwise and Zoho.
Lastly, our preferred method of sync is google sync and here's more on that, and actually zapier is the most complete method of syncing to any platform (over 250 and many CRMs included)