I agree as well. I've started to use the Apple Reminders app (as simple as it is) because I can pull it up during a meeting while I'm writing notes with Notability so I can record my tasks from a meeting. I really don't want to go backward, but I've changed to other apps that support split screen on my iPad Air2. It really is a huge benefit productivity wise.
Thank you so much for your feedback, I'm pleased to inform you that this feature has been confirmed and will be coming to "Todo 9". In- fact the feature has already been implemented and and is currently available for in our public beta.
For persons interested in joining our beta testing experience please visit: http://appigo.com/beta/
Please bare in mind that if you opt to test the beta version please ensure you create a complete iTunes back up of your device before installing.
I've registered a couple of times for the Beta. When will I get notification on that?
We're hoping to have the App shipped within a few weeks, unfortunately at this time we're unable to state a specific date. However we're very close to a release and have been shipping updates each week to our beta testers.