Harvest Time Tracker for iPhone is just one piece of the puzzle. It is used in conjunction with Harvest, the online subscription-based time tracking and invoicing system. While this app allows you to track time for the tasks you are working on for a given project, the actual management, invoicing, and expense tracking of those projects are handled by the online system.
First, you use the online system to create the projects and tasks you want to work on. When you run Harvest Time Tracker on your iPhone, you setup account information so it can connect via wifi and synchronize the projects and tasks with the device. Once they are on the device, it is not necessary to have Internet access until you need to sync up again to update the online system.
Actual usage of the app is simple. The current day is always shown and you just add new time sheet entries as you work on project tasks. You select the project, the task, and then either start a timer, which ticks away irregardless of whether the app is running or not, or just enter a duration. You can also enter notes.
You do this for all tasks and projects and then when you sync with the online version of Harvest it is automatically updated. Synchronization occurs when you start the Harvest Time Tracker app but can also be initiated by shaking the iPhone.
If you are a freelance worker or can otherwise benefit from a streamlined but fairly robust online time management system, Harvest might be for you. I won't review the actual online system here, but suffice it to say the iPhone app works well although it would be nice if you could also use it to enter expenses for such things as travel and meals. Fortunately the developer does allow access to some of these features from the iPhone's built-in Safari web browser.