Believe it or not, I use an old DOS program that called CheckTrax.
Started using it in 1994 as a check book and have migrated it through several Windows upgrades.
I have used it to track credit cards, loans, mortgages, savings accounts, two kid's college loans, and of course the checkbook.
It is extremely easy to use, but Im not sure you can even find it now.
Edit: Name of program is Check Tracker. copyright 1993 SoftDisk Publishing.