Following Aleh’s entry on contact management I decided to give CoBook a try. But it’s really buggy and doesn’t seem to work well with Yosemite. The Latvian company which built CoBook was recently bought by FullContact and while they’ve promised to keep everything running, right now it’s unusable.
The problem for me emerges after I have had cobook open for a few minutes. (When I first open it it works fine). What happens is when I try to modify a field in the contact (such as add tags or notes), I put the cursor in the box with the plus sign. Normally this should allow you to type and little dropdown box should appear to select which field you modify (eg. tags, notes etc.). But what it does is jumps to the search field on the right to search for new contacts. (See screenshot).