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Nina Kolari
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Building with AI

5 Apps You Can Build Instead of Paying for Subscriptions

A daily planner, journal, workout log, time tracker and budget to build with AI instead of paying yearly, with a starter prompt for each app.

9 min readBy Nina Kolari

You can build your own daily planner, journal, workout log, time tracker and budget with AI instead of paying for Structured, Day One, Hevy, Toggl Track and YNAB. Each first version takes a few hours to a weekend. Together, those subscriptions cost more than $300 a year at their lowest listed prices. The budget comes with one warning: skip bank syncing.

A lot of the apps you pay for every year come down to a list, a form and a chart. Structured is a task list on a timeline. Hevy is fast data entry for sets, reps and weight.

You don’t need anyone else to want your version. It only has to beat the subscription for you.

I run canaibuild.com, a directory answering one question for each app: can AI build this for your own use? Sometimes the honest answer is to keep paying.

If you want help when a build gets stuck, join my Idea to App with AI community.

Which apps can you build with AI instead of paying for a subscription?

These 5 are the easiest wins from canaibuild.com. Four got a clear yes for a personal build. The budget got a “yes, but”.

App Replaces What you stop paying First version Full build guide
Daily planner Structured Pro $19.99 a year 3–6 hours Build a planner like Structured
Private journal Day One Silver $49.99 a year 3–6 hours Build a journal like Day One
Workout tracker Hevy Pro $23.99–39.99 a year, varies by region [VERIFY] 4–6 hours Build a workout tracker like Hevy
Time tracker Toggl Track Starter $9–10 a month per user 2–4 hours Build a time tracker like Toggl Track
Manual budget YNAB $109 a year 4–8 hours Build a budget like YNAB

Prices and build times come from the canaibuild.com guides, reviewed on 16 and 17 September 2026. Build times are estimates for a working first version, not a polished app.

Every prompt below asks for the same things: one file, data stored on your device, an export button, and a layout readable on a phone. Paste one into Claude, ChatGPT or Lovable and build from there.

1. A daily planner (instead of Structured)

Your day as a timeline of time blocks. Drag a block to move it, set tasks to repeat daily or weekly, and see the week ahead.

The hard part is the feel. Matching Structured’s smooth drag-and-drop takes a couple of extra evenings of testing on your own phone.

Copy this:

Build a personal daily planner web app for my own use, in one HTML file with no framework and no server.

Show today as a timeline with tasks as time blocks. Let me drag a block to reschedule it, and set a task to repeat daily or weekly. Add a simple week view.

Save everything in localStorage with a version number. Add Export JSON and Import JSON buttons.

Make it work well on a phone screen 375px wide. It’s a personal tool, not a product.

2. A private journal (instead of Day One)

An entry box stamped with the date, a photo per entry, and a calendar of past entries. Export everything as text or JSON.

Treat privacy as the main feature. The canaibuild guide recommends encrypting entries on your device rather than storing your journal as plain text.

Copy this:

Build a personal journal web app for my own use, in one HTML file with no server.

Each entry gets an automatic date and time, text, and one optional photo. Show past entries on a calendar.

Encrypt entries in the browser with a passphrase I choose, and explain in a README where my data lives and what happens if I forget the passphrase.

Add Export JSON and Import JSON. Make it readable on a phone 375px wide.

3. A workout tracker (instead of Hevy)

Saved routines, sets logged with weight and reps, and last session’s numbers filled in for you. It spots personal records and draws a progress chart per exercise.

Speed decides whether you keep using it. Test it mid-workout, with sweaty hands, before you cancel anything.

Copy this:

Build a personal workout tracker web app for my own use, in one HTML file with no server.

Let me save routines, then log sets with weight and reps. Fill in each exercise with my numbers from last time. Flag new personal records and show a progress chart per exercise.

Logging a set must take one or two taps. Save in localStorage with Export JSON and CSV.

Make it work one-handed on a phone 375px wide.

4. A time tracker (instead of Toggl Track)

A start and stop timer with a description, colour-coded projects, manual entries for time you forgot, and daily and weekly totals. It exports to CSV for invoicing.

You lose two things: sync across devices and automatic idle detection. If you track from one browser, neither matters.

Copy this:

Build a personal time tracker web app for my own use, in one HTML file with no server.

Add a start and stop timer with a description, projects with colours, and editable manual entries. Show daily and weekly totals by project.

Keep a running timer safe if I refresh the page or open a second tab.

Save in localStorage, with CSV and JSON export. Make it readable on a phone 375px wide.

5. A manual budget (instead of YNAB)

Add your income, give every amount a category, log spending against it, and see budgeted versus spent each month. Leftovers and overspending carry over to next month.

This is the one with a “but”. Skip automatic bank syncing. Connecting your bank accounts is a real security job, and it’s safer with an audited service. If typing in transactions sounds like a chore, keep paying for YNAB.

Copy this:

Build a personal zero-based budget web app for my own use, in one HTML file with no server and no bank connection.

Let me add income, assign it to categories, and log transactions by hand. Show budgeted versus spent per category each month, and carry leftovers or overspending into the next month.

Save in localStorage with Export JSON and CSV. Make adding a transaction fast on a phone 375px wide.

Which one should you build first?

Start with the app you open most often, because you’ll test it every day.

  • You plan your day each morning: the daily planner.
  • You write most evenings: the journal.
  • You train three or more times a week: the workout tracker.
  • You bill clients by the hour: the time tracker. The CSV export feeds your invoices.
  • You already budget by hand in a spreadsheet: the budget. Otherwise, start with something lower stakes.

Build the smallest version first. My guide to what to build in a first version shows what to cut, and Simple, Lovable, Complete explains why small still has to work end to end.

What won’t these apps do for you?

Homemade apps trade polish and sync for control and a lower bill.

  • Sync across devices. Data saved in your browser stays on that device. Your phone and laptop won’t share it without extra work.
  • Backups. You own your data, so you also own the backups. Export it on a schedule you’ll keep.
  • Polish. The paid apps have years of small refinements. Yours will feel rougher at first.
  • Bank connections. Leave them to audited services.

Keep paying when sync across devices is the reason you use the app, or when the subscription costs less than an evening of your time. Nothing here is worth building if you won’t use it.

Which AI tool should you use to build them?

Any of Claude, ChatGPT or Lovable will build these from the prompts above. If you want a web app without touching a code editor, I’d start with Lovable. My vibe coding tools comparison covers the rest, and Building With AI explains the wider process.

If you’d rather build something no subscription covers, start with how to come up with an app idea.

Frequently asked questions about building apps instead of paying for subscriptions

Can I build my own budgeting app instead of paying for YNAB?

Yes, for manual budgeting. Logging income, assigning it to categories and tracking spending is a weekend build. Skip automatic bank syncing, because connecting bank accounts safely is a job for audited services.

How long does it take to build a simple app with AI?

A first working version of these apps takes about 2 to 8 hours, depending on the app. Making it pleasant enough for daily use takes a few more evenings. These are estimates from the canaibuild.com guides, not guarantees.

Is it worth building an app to save a subscription fee?

It’s worth it when you’ll use the app often and the subscription costs more than your build time is worth to you. A $109 yearly budget app is a stronger case than a $20 one. Build for the fit, not only the saving.

Where is my data stored in an app I build myself?

In the prompts above, your data stays in your browser on your own device, in localStorage. Nothing goes to a server. That also means you’re responsible for exporting backups.

What do homemade apps lose compared with paid apps?

Mostly sync across devices, automatic backups and polish. Some paid apps also have features worth paying for, such as secure bank connections in budgeting apps. Each canaibuild.com guide lists what you give up.

Sources and further reading

Prices checked on 16 and 17 September 2026 through the canaibuild.com guides.