A countdown timer alternating work and break intervals, with a log of completed sessions, is genuinely simple — one of the more approachable builds in this whole library.
Build it
Effort: an eveningRunning cost: $0/mo to start
Why CanICodeThis says Build it
A countdown timer alternating fixed work and break intervals is basic front-end timer logic
Logging each completed session with a subject tag is ordinary CRUD
A weekly chart of study time by subject is straightforward aggregation
The parts that'll cause problems
Browser tab notifications and sound alerts when a timer ends need care to work reliably across tab-switching
Syncing session history across devices needs a real account and backend, beyond a purely local tool
Detecting whether you actually stayed on-task (not just that the timer ran) isn't something a timer alone can verify
How I'd build this
frontend
Astro or Next.js
database
Turso (SQLite)
hosting
Cloudflare Pages
MVP scope
A countdown timer alternating work and break intervals
Log each completed session with a subject tag
A weekly chart of study time by subject
Postpone to v2
Cross-device sync with an account
Custom interval lengths per session type
Browser notifications when a timer ends
What it actually costs to build
AI agent — with a subscription (Claude Pro/Max, Cursor, etc.)
$0 marginal
AI agent — pay-per-use API, no subscription
$16–$27 one-time
Hosting, once it's running
$0/mo (free tier)
Domain name, if you want your own
~$12/yr
Existing tools solving a similar problem typically run $9–$12/mo — see how they compare below.
The build prompt
Build me a Pomodoro study timer: a countdown timer alternating work and break intervals (25/5 minutes by default, adjustable), logging each completed session with a subject tag, and a weekly chart of study time by subject. Local storage is fine to start — no account needed.