The importance of this cannot be overstated. I used to use Mint when I was in college, but got sick of them pushing credit cards on me, and the uncomfortable feeling of giving a service full access to my bank account. I tried tracking all my expenses in a spreadsheet for a year, which worked fine, but wasn't the most flexible system (or rather, it very quickly became a UX monstrosity).
Now I use hledger, which has been fantastic. I back up the file to a shared drive that's sync'ed to my phone, so every time I get a message from the bank or pay with cash, I can immediately note it down (this would have been much less workable before I found the "cone" app) and track my spending across dozens of accounts.
There are some improvements that could be made as to the visualization of data, which I might write a quick webapp for, but in terms of simplicity, robustness, and ease of use, plaintext is definitely the way to go.
Now I use hledger, which has been fantastic. I back up the file to a shared drive that's sync'ed to my phone, so every time I get a message from the bank or pay with cash, I can immediately note it down (this would have been much less workable before I found the "cone" app) and track my spending across dozens of accounts.
There are some improvements that could be made as to the visualization of data, which I might write a quick webapp for, but in terms of simplicity, robustness, and ease of use, plaintext is definitely the way to go.