when I got my First smartphone I was looking for one, too. MyPhoneExplorer was the best I found, but it was not satisfying at all. I also Tryed to Sync my Callender via IMAP. But the result was also not very pleasant.
Every Tool I tried hat problems and I got doubled Appointments (assigning failed) wrong Start and End Times (problems with Time zones) or Series Appointments changing there Start and End Times (problem with clock change). It was very frustrating.
After weeks I tried the google calendar and it worked perfectly from the first moment, but I was not really happy with giving google an overview of all my dates.
So after some time I installed Owncloud on my Synology NAS as CalDAV and CardDAV Server (i prefer Synologys Cloud Station for File Sync) and use CalDAV Sync and CardDAV Sync on my Phone and I’m very Happy with this solution.
I just want to say, that Smartphones are made for the cloud, you will find really nice Tools to do thinks over the cloud but trying to do thinks locally with a cable can be torturous.