Time tracking across devices with tagging

I'm looking for a quality time-tracking app/system. Here are the features I need: * Works on both OS X and iOS with syncing (iCloud or Dropbox preferred) * Includes tag/label system to allow for filtered analysis Most of the apps I've tried don't meet one or both of these criteria. I have no use for billing features, so those are of no concern to me. My environment is such that I work on many similar projects across multiple buildings. I also attend meetings with people from different buildings and departments, often in multiple configurations. I want to be able to drill down and see how much time I am devoting to each project, each building, each department, each staff member, and so on. The only way I can think this might work is with tags. Projects alone don't allow this.