Timo has a real good feel for what makes an app usable. And his responsiveness to his supporters is awesome. I have not looked at his other apps, mainly because I have no need for them. I'm sure they are useful as well.
I have looked long and hard for another PC-based free-form, tree-outliner style of database ever since Treepad went out of business. (I understand the developer passed away). I've been using this sort of personal informaton manager (PIM) since the early days of Mac (80s), but the newer apps have wandered off from the original versions, such as "More" and "ThinkTank".
I currently use "My Notes Keeper" for organizing personal data. I think the developer of this PC app is no long supporting it.
I think Timo could gain a quick and large piece of the marketplace, given how impressed I've been with Diarium, if he were to build a PIM app for us...Others have tried and made it either way too complicated or expensive...Just saying...
Diarium version:
Win 11, IOS, Android