Can AI build a subscription tracker app like Rocket Money?

Build a personal subscription tracker web app to replace Rocket Money Premium for my own use.

Tech rules:
- Plain HTML, CSS, and vanilla JavaScript in one file. No framework, build step, account, or server.
- Store all data in localStorage under one key, with a version number.
- Never ask for or store bank logins, card numbers, or account numbers.

Data model:
- Subscription: id, name, amount, currency, cycle (weekly | monthly | quarterly | yearly), startDate, nextRenewal (YYYY-MM-DD local), trialEndsOn (optional), category, status (active | cancelled | paused), cancelUrl, notes.

Features:
- Dashboard: total per month and per year for active subscriptions, grouped by currency.
- "Next 30 days" list, sorted by date, with trials ending shown first in a warning color.
- Mark as cancelled keeps the record and shows total saved per year since cancelling.
- Sort by monthly-equivalent cost so the most expensive items show first.

Edge cases the build must handle correctly:
1. Monthly-equivalent cost: weekly x 52 / 12, quarterly / 3, yearly / 12. Round only for display.
2. A renewal on the 29th, 30th, or 31st rolls to the last day of shorter months, then returns to the original day when possible.
3. When a nextRenewal date passes, advance it by one cycle automatically on load, as many cycles as needed.
4. Never add different currencies together. Show separate totals.
5. A trial with no amount yet still appears in "Next 30 days".
6. Cancelled and paused items don't count toward totals.
7. Use the device's local date, never toISOString(), to decide what "today" is.

Reminders:
- "Export reminders (.ics)" creates one all-day event per upcoming renewal and trial end for the next 12 months, each with an alert 3 days before.

CSV import:
- "Import transactions CSV" accepts a bank or Rocket Money transactions export. Let me map the date, description, and amount columns.
- Flag merchants that appear at least 3 times with amounts within 10% of each other and intervals of 6–8, 28–32, or 360–370 days as "likely subscriptions". Let me confirm each one before it's added.

Backup:
- One-click "Export JSON" and "Export CSV". "Import JSON" restores a backup after confirmation.

Layout:
- Mobile-first, readable at 375px wide.

Exclusions:
- No publishing, App Store submission, accounts, bank linking, payments, cancellation services, or social features.

Write a short README explaining where the data is stored, how to export and restore it, and how to import the .ics file into a phone calendar.

Keep it under 800 lines. This is a personal tool, not a product.

What is the short answer?

Yes. AI can build a subscription tracker that replaces Rocket Money Premium, which runs about $7 to $14 per month on a pay-what-you-think-is-fair slider. For one person, a private tracker with totals and renewal reminders takes 2–4 hours to build.

The trade-off is bank linking. Rocket Money finds subscriptions by reading your transactions. A self-built tracker doesn’t touch your bank, which is more private, but you add subscriptions yourself or import them from a CSV once.

Option	Best for	Upfront cost	Ongoing cost	Main limitation
Build a rough prototype	People who want one list of every subscription with a monthly total	$0 and 2–4 hours	$0	Date math on renewals is untested
Build a daily-use personal version	People who want renewal reminders on their phone without giving an app their bank login	$0–$20 and 6–8 hours	$0	Subscriptions you forgot won’t appear unless you import a bank CSV
Keep paying for Rocket Money Premium	People who want automatic detection, bill negotiation, and cancellation help	$0	$7–$14/mo	Your bank data sits with a third party

The ready-to-paste starter prompt at the end of this page builds the daily-use version.

What should the first version include?

The first version needs one number you trust: what you pay per month across everything. Then it needs to warn you before each renewal.

• A list of subscriptions with price, billing cycle, and next renewal date
• Monthly and yearly totals that convert weekly and annual plans correctly
• A 30-day renewal list with free trials on top
• Reminders exported as a calendar file your phone already knows how to handle
• A CSV import that suggests likely recurring charges
• Deliberate exclusion: no bank linking and no cancellation service. The build never sees a password or card number.

What can AI build reliably?

ChatGPT and Claude handle this app well because it’s a list plus arithmetic. A working tracker with totals, sorting, and categories comes out of the first prompt.

Things AI gets right quickly:

• Add, edit, and mark-as-cancelled screens
• Totals per month and per year, sorted by cost
• A “saved since cancelling” figure that makes cancelling feel worth it
• An .ics file generator for calendar reminders

The .ics trick matters. A web page can’t send notifications when it’s closed, but your phone calendar can. Export the file once a month, import it, and your calendar reminds you 3 days before each renewal.

Where will AI need human help?

Date math needs your testing. A subscription that renews on January 31 should renew on February 28, then March 31. AI often drifts it to March 3, or pins it to the 28th forever.

The recurring-charge detector also needs review. Your grocery store appears every week at varying amounts, and the detector should not flag it. Check the suggestions and confirm each one manually.

Other checks:

• An annual plan renewing next year shows 1/12 of its price in the monthly total
• Two currencies stay in separate totals
• Past renewal dates advance on their own when you open the app after a month away

Privacy is the strongest reason to build this. Your subscription list stays in your browser. Keep bank CSVs out of shared folders after you import them, since they hold your full transaction history.

Can I get my data out of Rocket Money?

Yes. Rocket Money’s transaction export works from the Transactions page on web or mobile. You apply filters, press Export, and receive an email with a download link. The CSV only downloads on a desktop or laptop.

The trap: this exports transactions, not your subscription list. Rocket Money’s detected subscriptions, cancellation history, and custom categories don’t come across as a separate file [VERIFY]. You rebuild the list from the transactions.

That’s what the starter prompt’s CSV importer is for. It looks for merchants that charge a similar amount on a weekly, monthly, or yearly rhythm and asks you to confirm each one. Export at least 13 months of transactions so annual subscriptions show up.

How long will it take and what will it cost?

Rough prototype: 2–4 hours and $0 on a free AI plan. You get the list, totals, and renewal dates.

Dependable daily-use version: 6–8 hours across a week, including the CSV detector, the .ics export, and month-end date fixes. $0–$20 if you pay for one AI month.

Rocket Money Premium costs $7–$14 per month. A $20 AI month pays for itself in 2–3 months. At the $14 end, one month of Premium nearly covers it.

These are estimates from reviewing the feature set, not measurements from a completed build.

Which AI tool or approach should I use?

Claude previews the single HTML file in the chat, which makes it easy to test totals before saving.

ChatGPT is equally strong for the first version. It also helps you clean up a messy bank CSV if the importer struggles with your bank’s columns.

Cursor is worth it later if you want to refine the recurring-charge detector without regenerating the whole app.

Lovable tends to add accounts and a hosted database. For a private money tool, that’s a step away from the privacy you’re building for.

What will I need to maintain?

Very little. There’s no server, API, or bill.

Recurring work:

• Export a JSON backup monthly
• Re-export the .ics reminders when you add a subscription
• Import a fresh bank CSV every 3–6 months to catch anything new

The tracker is only as complete as your last check. Put a calendar event every quarter to review it. If you like streaks, add a monthly “review subscriptions” item to the habit tracker build.

Should I build it, buy it, or reduce scope?

Build it if you want a private list of subscriptions with totals and reminders, and you’re fine adding new ones yourself.

Buy it if you want bill negotiation or someone to cancel services for you. Rocket Money’s negotiation charges a share of the first year’s savings, and that service has no DIY equivalent. If you also want a full budget, look at the YNAB build instead.

Reduce scope if you have fewer than 10 subscriptions. A single list with next renewal dates and the .ics export covers it in about an hour.

Recommendation: build it. A tracker is the easiest money-saving build on this site, and it pays for itself the first time it catches a renewal you meant to cancel. Keep Rocket Money only if you actively use its negotiation or cancellation concierge.

What if I wanted to ship this to other people?

Shipping this to others means bank connections through a data aggregator, security reviews, and handling other people’s financial data. That’s a regulated, expensive product. The personal tracker above avoids all of that by never touching a bank.

Starter build specification

• User: You, for your own use.
• Problem: Paying $7–$14 per month for Rocket Money Premium to see and track your subscriptions.
• Core workflow: Add a subscription, see the monthly total change, get a calendar reminder 3 days before renewal.
• Required features: Subscription list, normalized totals, 30-day renewals, trial warnings, .ics export, CSV import with recurring-charge suggestions.
• Deliberate exclusions: No accounts, no bank linking, no multi-user support, no store submission.
• Data ownership: Stored in localStorage. Exported as JSON and CSV. Transactions imported from any bank or Rocket Money CSV.
• Definition of done: You import 13 months of transactions, confirm at least one monthly and one annual subscription, and the monthly total matches your own calculation. A subscription renewing on the 31st shows the correct date in February.

New to building? Start with can AI build an app for me.

Sources and verification

• How much does Rocket Money cost (Rocket Money): Premium price range of $7–$14 per month, 7-day trial, bill negotiation fee of 35–60% of first-year savings.
• Exporting transactions (Rocket Money Help Center): CSV export steps and the desktop-only download.
• Rocket Money pricing 2026 (Finny): free plan includes subscription tracking [VERIFY on Rocket Money’s site].

This app was not built and tested for this page. The verdict is based on Rocket Money’s documentation and a review of the feature set. Rocket Money’s price was checked on September 24, 2026.

Reviewed on September 24, 2026.