Yes, that's what I found. It's a bit of a hassle and I only signed up for the free service for one-day since that was the only option for that and I didn't feel like doing it each day I was there.

The pay-for service (though free for plat) I signed up for five days, but I constantly had to log in and out as I switched devices so it was a bit of a hassle.

There was not an option for three devices to each have a separate log in as once you chose one of the pay ones, the others disappeared.