Yes it exists. No, I would not recommend it for an initial EMT program. We have beat this dead horse to the mortuary and back on these forums. I'd recommend a quick search.
Honestly though. Why not just go through a traditional EMT program. It's a few months, and many places offer night and weekend courses to accommodate people with busy schedules. I did mine while I was in high school.
I did PERCOM's Paramedic program, and it worked out great for me. But, that was NOT for my initial EMT. I cannot stress how much easier it will be if you just suck it up and go to a normal in-person EMT program. The administrative and regulatory hurtles to complete an online EMT program are not worth it, and by the time you are all said and done with the silly distance clinical paperwork, finding a medical director for yourself, convincing your state to license you, and then a company to hire you, you probably could have completed 10 normal EMT programs.