The November 9, 2010 update of Pocket Frogs added a feature to the menu screen called Weekly Sets.

What is a Weekly Set?

A weekly set is a group of frogs. The weekly set screen will show you the types of frogs that you need to collect in order to complete the set. Below the frogs, it lists the reward that you will get if you complete the set.

How do you Redeem a Set?

Each frog on the Weekly Set screen has a dot below it. If you have one of those frog types in any of your habitats, the dot below that type of frog will light up.

Once all of those dots are lit up, you can tap "Redeem Set" to get the reward listed below the frogs. Redeeming a set doesn't remove the collected frogs from your habitat. You keep the frogs, and you can sell them if you wish. It won't take away your reward if you do so.

When are New Sets Released?

A new set is released every Wednesday at midnight. You can tap "Get New Set" to find out if there is a new set available.

Where Can I See the Sets that I have Completed?

You can see all of your completed sets by tapping the Completed Sets button. It will show a row for each weekly set that you have completed, showing the types of frogs that you collected, and the name of that set.