I used iBoardA.com my last two trips and had no problems. They do it for free, but I think they are planning for donations for those that fly a lot. I will probably send a donation. I used checkinsooner.com on my last WDW trip and it worked fine also, but they now require a paid membership.
There are those that say these services are not fair, that the confirmation number belongs to the flyer and they are the only ones to use it to check in. However, if you go by the letter of the law vis-a-vis SWA, it is technically illegal for anyone but the owner of the confirmation code to check in. That means that maybe these services are illegal, but so is your relative or friend at home for checking you in. I take my laptop to WDW and if I have a flight that does not interfer with my fun, I check in myself. If not, I use a service.
