Funky Frog allows you to target messages or news to a specific group of Subscribers.
A Topic is similar to a Sub-Group as it allows you to target your messages to specific groups of subscribers.
Unlike Sub-Groups, however, which are assigned to Subscribers by an Admin user, and cannot be opted out of, a Topic is a group the Subscriber can choose to opt into or out of themselves.
To set-up Topic Preferences, the Subscriber should go to the 'Alert Preferences' section of the App (by tapping the 'Hamburger' icon at the top left of the screen). From here it's possible to opt into or out of specific Topics.
Targetting a message to a specific group (or topic), you select the Topic when sending the message from the Control Panel.
So for example, if you want a message to go to subscribers who have opted into the 'Friday Night Tennis' topic, then you select Topic 'Friday Night Tennis' when sending your message.
You can setup as many Topics as you want and subscribers can opt into as many as the want.
Note though that targeting messages to specific Topics means that only subscribers who have opted into this topic will see the message and receive a notification.