Grit Ladder

Grit Ladder is a logbook built around how rock tumbling actually works: four grit stages, roughly a week each, with a full wash between every one. Load a barrel and the app does the math for you — how much grit for the rocks you're adding, whether you need ceramic media to fill it out, and where the water line should sit. It warns you before you mix stones that are too far apart in hardness, so a soft piece of fluorite doesn't get pitted sitting next to agate. Every running barrel shows its rung on the ladder, day X of N, and when it's next due for a look. When a stage finishes, the app walks you through the wash, a photo of the rocks, and the step up to the next grit — coarse, medium, pre-polish, then polish. Keep a Rock box of everything you've found — beach agates, creek jasper, gravel-pit quartz, gem-show rough — with a photo, material, Mohs hardness, and origin for each. A built-in reference of common tumbling materials and their hardness is there when you need a quick answer. Track your grit shelf in pounds and ounces so you know before you load a barrel whether you actually have enough 220 or cerium oxide left, and watch finished batches fill a jar with a before-and-after photo for every one. Works for rotary and vibratory tumblers alike. No account, no ads, no internet connection required — everything stays on your device. What it won't do: it doesn't identify rocks from a photo, it doesn't sell you anything, and it doesn't need the weather. It's a logbook, not a shop.