Play-dough or model magic clay
(If you get the plain white, you will need to mix paint into the white clay to make other colors.  If your learner is on the younger end, it is recommended that you prepare the clay before class.  You may want to get three primary colors (red, yellow and blue) plus the white and black.  You can pre-make other colors like green, purple, orange, brown by mixing the primary colors before class, so that your learner has all colors ready for use while following along with the instructor.)
Clay tools, toothpicks, rolling pin, etc.
Paint
Paintbrush
Cardstock to put your creation on

Learners will not need to use any apps or websites beyond the standard Outschool tools.