RA like ASU with option to add credit at end of course?

[LastFrontierLearner]

Are there any other RA online classes like ASU's Earned Admission that give the option of making the class for-credit at the end of the course instead of the beginning? I've tried Googling and searching through the forums here but haven't come up with anything. 

EDIT: For a bit of context, my 13-year-old twins are homeschooling and they are chomping at the bit to start college classes. They definitely have the reading ability and motivation, but I'm looking for options where they could potentially earn RA credit with a bit of a safety net as they adapt to the rigor of college-level classes.

Thank you - I have already learned a ton from all of you!