If there’s one thing I love, it’s a personal finance app or hack that gets me granular AF about my finances. Either can be used little picture stuff (tracking monthly expenses) or big (i.e., planning for the future), but both of them are awesome (and free).
Personal Capital - (little picture, but mainly big) - This app works best as a dashboard for ALL of your accounts (savings, checking, retirement, credit card, investment, you-name-it, etc.) to give you a snapshot of your net worth. Interface is also gorgeous (you feel so banker-y!). What they also have is, based on your current retirement accounts, a fee analyzer to see if you’re getting the most bang for your buck.
Google Spreadsheets (depends) - Call me old-fashioned, but I use a spreadsheet to do my budgets. I also manually enter my projected and actual income from my freelance clients. Doing this allows me to keep a bi-weekly record of outstanding amounts of moolah that should be paid to, well, me. (Staying on top of this is the first step to avoiding conflict and misunderstandings down the line.)
I've tried others, but these are the ones that I've used for several years or more because they've gotten me (and kept me) on top of my own personal finance game.
I've heard good things about YNAB, and I've tried EveryDollar and Mint, but these two have been with me for at least five years. (So you should check them out, too.)