GridCalc: An RPN Spreadsheet for iOS
tailrecursion.comI built GridCalc because spreadsheets on phones feel fundamentally wrong.
On desktop, spreadsheets work because you can see formulas, references, and structure all at once. On mobile, that collapses. You’re constantly panning, zooming, tapping small cells, and losing context.
RPN (Reverse Polish Notation) removes parentheses and operator precedence by using a stack. Instead of writing = (a + b) * c, you enter a b + c *. The order of operations is explicit and linear.
GridCalc combines those ideas: a visible RPN stack with a reference grid.
It’s built for quick, ad-hoc modeling on a phone: loan calculations, position sizing, cash flow scenarios, engineering back-of-napkin math.
It’s not trying to replace Excel. It’s trying to make mobile calculation feel native instead of cramped.
Happy to answer questions about design decisions or implementation.
This is awesome! The design is slick, and it really does feel right at home on a portable device. Appreciate the work that went into this.
Even more so, huge kudos for the performance tuning! The app launches instantly, so much so that I was initially a bit shocked. I'd forgotten what it feels like to tap a button and have something functional appear on screen with zero delay. When even the simplest apps have loading screens (and even built-in Settings/Reminders/Notes/Phone/etc. have a delay), this was really refreshing to see! I legitimately force-quit a bunch of apps on my phone to compare and nothing comes close on cold launch. Great work!
Thank you! I spent a lot of time eliminating launch-time work. Most state is precomputed or lazily initialized after first render. I wanted it to feel like a calculator, not an app.