I have also used Memrise, one of the courses on radicals. Should probably go through that again.
As Joseph said, Skritter is supposed to be good, but I haven’t used it much.
There are two apps that can be helpful for learning to write characters and include stroke order which you can turn on and off.
They are ‘Chinese Skill’ and ‘Hello Chinese’.
Pretty similar in their systems, but slightly different.
Here is what Hello Chinese looks like,
Chinese Skill is similar,
It seems to me like the Hello Chinese app has a few more options. In each though, you can practice the characters with or without guidance.