This app calculates baker’s percentages. Indicate the desired quantity of loaves and an individual gross weight, along with a few other key values, and this form will calculate the weights of subsequent ingredients for the main dough and levain. The levain is assumed to be a build of equal parts of bread flour and water (100% hydration).
Please let me know if and how this app can be improved! (I know, it is not really an app but a mobile-ready webpage. There is nothing to download and install.)