In version 1, there were separate tab pages for "Sounds" and "Scripts", each offering two options; the ability to play sounds or run scripts at the start and/or end of breaks.
Version 2 still has these features, but can do much more. So, instead of having numerous tab pages, it combines them into an "Actions" page:
In addition to sounds and scripts, other actions include the ability to display a notification (with an optional sound), fade out the currently playing sound (useful at the end of the break), flash the screen a custom color, and speak some text with speech synthesis. Several scripts are provided, too.
To add an action, simply click the button in the top-right corner of the window, to display a menu of available actions:
(When you first click this button, the scripts won't be there, and there will just be "More..." item at the end; choose this to install the scripts.)
The first bunch are the various actions, followed by scripts, which are like customizable actions. At the end of the menu are items to open the Scripts folder in the Finder, so you can edit or add scripts, and go to the Time Out Extras page to download more scripts.
Once you add an action, you'll see a header row with the name of the action and some other controls:
You can use the interval picker and pop-up menu to indicate when to use the action. The interval picker enables you to offset from the action stage by a number of seconds, minutes or even hours (click on the units to change them). Instead of just being able to play a sound at the start and/or end of a break, in version 2 you can choose from many more times, including before due, after skipping, and more:
After those controls is a Preview button, that will demonstrate the action. And a button to remove the action.
Here is a brief video to demo the feature: adding a Play Sound action to play a long music track, and a Fadeout Sound action to make it fade out when the break successfully finishes. (You might instead want to have it fade out for any end, otherwise it'd keep playing till done if you skip.)