What they are
Four small calculators for kitchen fermentation and dough: bread, yogurt, lacto-ferments, and pasta and noodles. Each one is a separate app that works offline once it has loaded, and each keeps its own settings on your device.
What the numbers are
Times and amounts are estimates from simple models, such as how fermentation speeds up in the warm and slows in the cold, adjusted for your starter, salt, milk or flour. Where a figure is the app's own rule of thumb rather than a measurement, the app says so. Your own jar, dough or batch is always the better guide: the apps ask you to check by look, taste or feel.
Made by
One person, for their own kitchen, and shared as free open source. There is no company behind it, no advertising and no account to make.
The source is on GitHub, including the calculation code and its tests.