I will turn your excel spreadsheet into a custom web app


About this gig
Is your business running on a spreadsheet that keeps breaking? Formulas that someone overwrote, #REF! errors, versions in five different emails?
I turn spreadsheets into simple web apps: forms instead of cells, calculations that can't be broken, and dashboards that show what matters at a glance.
WHAT YOU GET
- An app built from YOUR spreadsheet and YOUR process
- Forms with validation instead of fragile cells
- Automatic calculations, totals and alerts
- Dashboard with charts and filters
- Import your existing data, export back to Excel/CSV anytime
- Works on computer and phone; can be installed as an app and used offline
- No monthly subscription; your data stays with you
EXAMPLES OF WHAT I'VE BUILT
Debt payoff planner with simulators and reports, habit and budget trackers, a loan portfolio manager used every day by a lending business.
HOW WE WORK
1. You send the spreadsheet and explain how you use it
2. I propose the screens and confirm scope
3. Build in stages so you can test early
4. Delivery with a short user guide
Send me your spreadsheet before ordering and I'll tell you which package fits.
Get to know Sebastian L
Freelance Web Developer and Founder
- FromArgentina
- Member sinceOct 2026
Languages
Spanish, English
My Portfolio
Other Software Development Services I Offer
FAQ
Do I need to pay a monthly fee?
No. You pay once for the build. If it needs hosting, I set it up on a free or low-cost plan in your name.
Who owns the code and the data?
You do. You get all the files, and the data stays on your device or your own hosting.
Does it work on mobile?
Yes. Everything I build is designed for phones first and also works on computers. It can be installed like an app.
Can you work in Spanish?
Yes, I am a native Spanish speaker and work fluently in English. I can build bilingual projects too.
What if I need changes later?
Each package includes revisions. After delivery, I offer support and can quote new features any time.

