it depends what you're drawing on your own and you doing it digitally is best to use flipclip ((high quatily animation)) if you want to one fame at time then you can use IBS paint ((its free on the app store)) or you could go on Ebay, Amazon, ect I get one of Animation Table ((its the best if you are doing if you have lots money because they are quite high to pay for)). Now if want to draw Sunset Animation best to it one fame at first start with desgin and then take it slow.