GridCalc - RPN meets spreadsheets, for iOS

Hi everyone! I’m Alan, the maker of GridCalc. I’ve always liked spreadsheets and RPN calculators, but neither feels right on a phone. Spreadsheets get cramped and formula-heavy. Most RPN apps stop at single expressions. GridCalc is my attempt to combine both: a grid-based execution model driven by an RPN stack. You enter values and operators step by step, persist intermediate results in cells, and retroactively edit any input while everything recalculates instantly. The design goal was simple: make structured, spreadsheet-like calculations feel direct and fluid on a mobile device. It’s a one-time purchase (no subscription). I wanted to keep it simple. I’d especially love feedback from engineers, finance folks, and long-time RPN users. Happy to answer any technical questions about how it works.