You've probably created a few ToDos in the app already. Did you know that you can also create ToDos for other folks and they can do it for you too? It's easy once you know how.
A good working example can help to explain everything -- let's say you want to create some ToDos for your husband ...
Here is a summary of what it takes. For many users, all of these steps have already taken place.
The first thing you will want to do is get all of your iStratus DayPlanner apps (like on iPhone and iPad) connected to the Cloud (Dropbox, actually). This allows your devices to synchronize with each other so that everything you see on your iPhone shows up on your iPad and vice-versa. You may have already done this when you first launched the app. If you're not sure, just tap on the Cloud tab in iStratus DayPlanner and you will get prompted to sign in to Dropbox; you'll be all set in no time (there are over half a billion users on Dropbox!).
Get your husband to install iStratus DayPlanner and when prompted to install, he should select the Cloud option (Dropbox). Remember that Family Sharing allows him to download iStratus DayPlanner for free.
You may already have a shared folder with him; if you don't, just create a folder called "My Husband" or whatever you prefer and then invite him to the folder (use the Dropbox website). After he accepts the invitation, you two can now share all kinds of useful information with each other. Okay, back to ToDos... go ahead and create a subfolder under "My Husband" and call it "Shared ToDos" or something like that. Now go into that folder and create a new ToDo (tap button in upper right and you will see) and assign it to your husband. That ToDo will show on your Calendar tab for you and for him.
Just give it a try and you will see how amazingly useful this is. You can share ToDos with family, friends, work, or whomever.