When we first started tracking our family finances, we tried out tools like Mint that show you a per-category breakdown of spending. Others, like YNAB, ask you to categorize every charge. As a result, we ended up wasting lots of time looking through highly repetitive spending like groceries until we got to interesting one-offs like a season ski pass.
That motivated us to build our own finance tracking tool.
As usual, I took a step back to think about the problem. When talking about personal/family finance, what do we actually want to keep track of? After talking to a few friends, I found out most people are interested in three aspects of their spending:
Total spending over a time period
Spending that is hard to keep track of
Major category spending trends over time
The most basic info helps users get an overview of their spending
Rare transactions are likely to mess up the budget
Show users' high-level spending changes