Good luck and everything, but I've never had this problem. And, if I ever did have that problem I still wouldn't enter my email address to get, well, what? What does giving you my email address provide?
Hm, maybe I need to make the value prop better, but the page does say, "What if there was an app that made you stop what you were doing and plug your laptop in before you could continue working? There is, and it's nearly here.
Interested? Sign up to be notified of the launch below"
I don't know how I can be much clearer?
How would that app be different from the popup? Both inform you that the laptop is about to run out of battery and that you should plug it in. It's your problem if you ignore it.
It will block you from doing anything else until you plug the laptop in, with a full screen overlay that doesn't dismiss until the laptop is plugged in.
If your MacBook is properly configured, it should hibernate, so that you can easily resume your work, after you plugged in power supply. So I see no benefit from this app...
That's one of the key points: Sometimes properly configured MacBooks don't come out of hibernation properly. Also, I'm also trying to get rid of the annoyance of seeing your laptop hibernate when you could have done something about it. Maybe that isn't a pain for you, but it's a pain for me.