Ask HN: Do you estimate your tax return throughout the year? Why? What tools?

I'm a contractor, startup founder, and investor. I spend tons of time aggregating data to determine what tax I owe at the household level (I'm married and my wife works) so I can 1) make quarterly estimated payments, and 2) not have to worry about sourcing cash or paying penalties at tax return time.

I haven't found a good tool to help with or automate any of this and I'm thinking about building one.

Do you care about this problem? How do you solve it? What's it worth to you?