📘 1000 Side Hustle Ideas Home ← Digital Products & Online Courses ← Mobile Apps & Simple Tools
HUSTLE #392 4.10 Mobile Apps & Simple Tools

Freelance Invoice and Time Tracking Micro-SaaS

💰 Startup Cost $0-50
⏰ Time/wk 10-15 hrs
📊 Difficulty ★★★☆☆
🏆 1st Month $ $100-$300
💵 Monthly Range $300-$1,500
⏱ First $ In 1-2 months
Gumroad, Product Hunt, own website
Build a lightweight web-based invoicing and time tracking tool for solo freelancers. Track time with a start-stop timer, auto-generate branded PDF invoices from tracked hours, send invoices via email, and track payment status. Solo freelancers need a simple tool that costs less than FreshBooks ($15/month) or Harvest ($12/month). Charge a one-time $29-49 fee for lifetime access instead of a subscription to attract freelancers tired of monthly SaaS bills.
🚀 First Step
Create a basic HTML/CSS/JS web app with a 'Start Timer' button, a project/client selector dropdown, and a localStorage-backed timer that calculates elapsed time and estimated invoice amount based on hourly rate.
  • Store data in the browser using IndexedDB — no server, no database costs, no privacy concerns. Freelancers love that their data lives on their own computer and you have near-zero operating costs
  • Use a simple tech stack (HTML, CSS, vanilla JS or lightweight framework) to keep the codebase maintainable by one person and fast to iterate based on user feedback
  • Launch with a 'lifetime deal' on Product Hunt — early adopters provide invaluable feedback and the Product Hunt launch can generate your first $5,000-10,000 in a week if executed well
🛠 Tools & Resources: HTML/CSS/JavaScript, jsPDF (invoice generation), Gumroad, Product Hunt, Netlify (free hosting)