Study.com offers ACE-approved courses, accepted by all of The Big 3 for college credit. They offer a considerable amount of courses that can be completed quickly. As of March 2017, Study.com membership costs $200/month and allows for 2 exams during that period. Additional exams can be unlocked for $70.
Courses are self-paced and include video content. This can be an advantage for people that learn from observing and listening. There are pass/fail exams at the end of each course and 70% or better is required on the exam to pass.