The current version has a bug where it won't allow you to add an Action that sends Alt + Tab, but this will be all fixed up in the next version. I'll be sure to post an update as soon as it's available.

Thanks!

Actually, this fix is already in the current beta version, available here: https://www.voicebot.net/Download/Beta/

I've attached a screenshot of the Press and Release Key action that will send an Alt + Tab.