[whpalmer4]

OmniFocus stores two items for each project: the date it was last reviewed, and the desired interval between reviews. If the last review date + desired interval for that project is in the future, the project will not be offered for review. When you tap the Mark Reviewed button, the last review date is updated to the current date.

On the iPad, there's no global way to see when every project is up for review, and what the associated review interval is. You can only see it by going to each project in Review mode, which can be difficult if you've been reviewing as you should! You can force a project into the Review mode at any time by tapping and holding on the project's title bar in the Project view and selecting Review from the popup. Along the bottom of the Review mode window you'll see a box showing the last reviewed date and the review interval.

All the review functionality does is allow you to systematically look at your projects, and if you subscribe to the "I want to review all my projects on the same day" school of thought, you don't really need to use it at all. Just open up Project view, and systematically scroll through all of your projects and look them over. Review mode allows you to stop part of the way through and resume later, but you could just put a note in your Inbox telling yourself where you were. Where the Review mode really shines is when you want to review different projects at different intervals, and/or not all on the same day.

Probably the easiest way to get all of your projects to review on the same day and interval if you don't have the Mac app is to contact the Omni support ninjas. They can temporarily sync your database to one of their machines, set the review parameters as you ask, and send it back to you. After that, you just need to be sure to review all of the projects on your desired review day, because failing to do so will result in your projects coming up for review on a different day.