At the bottom of your project, you will see the navigation bar about management.
Find the icon (looks like a pile of paper) and tap on it to enter the frame manager.
Here, you can
1. Long tap on the frame to move it around.
2. Tap on the "Select" on the upper-right corner and select one or multiple frames to delete.
3. Single tap on a frame to duplicate, repeat, delete, or add tag to the frame.
* Tag is a premium feature available for Creativity 365 subscribers.