Nima has full support for Events. You can trigger Events with a keyframe during your animation, which can run any custom code at runtime. Examples include: telling your code when to play a sound effect, when to fire a particle emitter, when to apply force during an animation (like a jump), and more. Events can be attached to any object (this can be used to provide extra context along with Custom Properties). You'll find Events towards the bottom of the Selection Panel.
Click on the plus icon to create a new Event. Double click on it to rename it. Then switch to animate mode and set a keyframe to trigger the event. Events are also visible in the hierarchy, so you can easily set a keyframe without having to first make a selection.
As you can see in the image above, Events will display a notification during playback of your animation.