I've gone through the Skritter Chinese 101 list with the style set to "simplified". I decided after that I want to learn both simplified and traditional at the same time. So I set the style to "both". Went back to studying and no traditional characters showed up. Even when I get to 0. I tried the manual add button but it says I have no lists to add from. Skritter Chinese 101 shows up in my lists but is listed as finished. How can I study both traditional and simplified?

You gotta start adding from the list from the beginning again. If you go to the study page, it should say that you’ve finished the list. Click on the name of the list, go to "Change Study Settings" and just tell it to add from the first section again.

Thank you!

On a side note I noticed a "remix" option in there. What does that do?

When you remix a list, you make a copy of the list that you can then edit: reordering, adding, deleting, renaming, etc. You wouldn't need to remix your own list, but you would remix any list you wanted to change that you don't own.