Ceramispace
For both iOS and MacOS
For iOS https://ceramispace.app/download
You have to pay for this app either monthly, annually, or forever. The app is not very expensive and is used to store all of your recipes, material inventory, and firing schedule. The one thing that the developer needs to implement is a log feature which is why the next app is here.
ClayLab iOS
ClayLab is a great app that allows you to take pictures of your piece, keep track of what stage they are at and what day you finished that stage at. You can add more about this piece by adding the form, clay body, weight, dimensions, glazes, underglazes, slips, and notes. This is the best app to keep track of your pieces. If you are a busy potter and are at a community studio or in school this app is a great way to keep track of everything.