Difference between OnwardFlights.com and FlyOnward.com?

I found a thread on NomadForum.io discussing OnwardFlights.com and FlyOnward.com, both services seem legit as many people on that thread have used them.

EDIT: FlyOnward.com now stopped working - see answers for more info

Each company provides the same service in appearance, but there seem some confusion.

User "lonelyblogger" wrote:

flyonward.com I booked a test ticket from Thailand to Vietnam and they sent me a Vietnam Airlines ticket from Bangkok to Ho Chi Ming city, the code was valid when I checked with VNA's website. I love it

Then user "andrewkent" wrote:

I just used onwardflights.com [...] I provided them with the confirmation number and date of the flight, the agent punched it into her computer, and she handed me my boarding pass without asking any other questions.

Finally, user "lonelyblogger" wrote:

I used both. Onwardflights.com photoshops tickets, Flyonward.com books real tickets. Onwardflights is cheaper for a reason.

I'm not sure if that last quote makes sense though as user "andrewkent" wrote before that he used this service and "the agent punched it into her computer". You would think that at that point the agent would find out if the ticket was fake? Or maybe she was not checking the data, just adding it as reference in her airline's database. Confusing.

The question that really matters: do both company provide a flight confirmation that can then be checked later on (i.e. by immigration or airport staff, when leaving or entering a country)?

If you know more: is there any difference in the service provided? Any details on these services/companies would be appreciated.