SheetMind AI
Most people using Excel don't write formulas fluently — they copy one from a forum, half-understand it, and move on. SheetMind AI puts an LLM directly inside the spreadsheet so you can just ask what a formula does, or ask for the formula you need, without leaving the sheet.
The challenge
Excel formulas are powerful but notoriously unreadable once they get past a few nested functions, and most users don't have a reliable way to ask 'what does this actually do' or 'what formula gets me this result' without leaving the spreadsheet and searching online.
An AI add-in only works if it fits the existing Excel workflow — if it requires copy-pasting data out to a separate chat window, most of the value of 'staying in your spreadsheet' is lost.
Approach
I designed SheetMind AI to live inside Excel as a native add-in, so the language model has direct context on the actual spreadsheet, formulas and data the user is working with, rather than requiring them to describe or paste it manually.
The product and packaging decisions mattered as much as the engineering here: shipping it as a self-serve product on Gumroad meant designing an onboarding and pricing experience that works without a sales conversation.
What I built
An Excel add-in that lets users query an LLM about their live spreadsheet.
- In-sheet AI chat with direct context on formulas and data, no copy-pasting required
- Explains existing formulas in plain language
- Generates new formulas from a plain-language description of what's needed
- Packaged and sold as a self-serve product on Gumroad
Outcome
SheetMind AI is a shipped, sold product — one of the clearer examples of taking an AI product from concept through build to a paying customer base without outside funding or a sales team.
This is the kind of product that only gets built end-to-end by someone comfortable owning design, prompt engineering, the Excel add-in integration, and the commercial packaging all at once.