The Mutant Year Zero Table Top RPG suggests that you take note what has been discovered on each grid. To make that easier, I build a little website that lets you take a short note for each cell.
You can get the simple tool as html on github as well as try and download it on itch.io
The page uses local storage, so your notes should not get lost, even when you close the browser, but you can also export and import your grid with annotations as a JSON file.
First wanted to use LibreOffice Calc. But I quickly got frustrated trying to set a background image. The first prototype was generated with ChatGPT, which managed to get a working version right away. Maybe this small html file is also useful outside the intended use with the table-top role playing game. GMs that don’t need or trust virtual table tops might get some mileage out of this as well.
Glumbosch's Schmiede 