Ten apps sounds like a lot until you realize money in grad school splits into distinct jobs, and no single app does all of them. Think of this as a toolkit, not a ranking. Pick the tools that match your actual problems and ignore the rest.
For planning, a true grad school budget planner app: YNAB, for people who want every dollar assigned before the month starts. EveryDollar's free tier, the free grad school budget tracker app most people start with, because free is the right price on a stipend. Goodbudget, for the envelope system devotees who like hard boundaries.
For tracking, a dedicated grad student expense tracker app: Rocket Money, which watches for subscriptions and bill creep in the background while you are busy with quals. Copilot, the iOS-first tracker that people actually enjoy opening, which matters more than it sounds. PocketGuard, which boils the whole question down to how much is safe to spend right now. Sometimes that single number is all you need.
For the spreadsheet loyalists: Tiller, which pipes transactions into a spreadsheet automatically, and the plain manual spreadsheet, which costs nothing and never breaks. Some of the most organized grad students I know run their entire financial life on a spreadsheet with strong opinions. Respect.
And for the question no budgeting app can answer, whether the stipend itself is enough: phdstipend.fyi. Its cost-of-living-adjusted offer reports compare real program stipends against real city costs, which is the cost of living adjusted PhD stipend number every other app on this list quietly assumes you already know.
The pattern across all ten: simple beats sophisticated, and used beats perfect. A free tracker you open monthly outperforms a premium suite you abandoned in October. Start with one, give it a semester, and add tools only when you can name the job the current set cannot do. The toolkit grows with the problems. Not before.