[ghaff]

I assumed (and I see there are) all sorts of online tools that purport to help with planning. Many people also set up websites these days. I assume these have affiliate links and the like but they're not exactly disruptive applications.

[basch]

Some of them all do one or a couple parts of what I described, but they are all designed to be "easy and simple" more than powerful. And I really doubt most of them do things like watch my credit card to keep track of how much has been paid out.

There's plenty of room for innovation, with some more imagination.