An Animation Frame is a distinct stage of the animation sequence of a design. On every animation frame, every element can have one entrance, exit or emphasis animation.
On the right-hand side of the editor, the Animation button has a number associated with it. The number in the Animation button indicates which animation frame you are working in.
As you change the animation frame you're working in, the number in the Animation button will change as well. If you're not working in the Animation Frames panel, Flexitive will remember what frame you're working in.
Keeping an eye on the animation frame you're working in is important if you are adding elements after you've started adding animations. When you add elements to the canvas after you've started adding animations, the element will be added as being visible with no animation on the frame you're working in.