Personally, I just want to get a graduate certificate from them so I can have a little bit of a better chance at getting into PhD programs at other schools. So in other words even if its not a great school to get a degree from is it worth going for grad certificate?
There is no such thing as a “good online school.”
Which graduate certificate?
Which PhD program?
I don’t know about the reputation of APU. However, http://www.worldcampus.psu.edu/ and http://umuc.edu/ both have long-established distance and online programs that are well respected. Your own home-state public U may offer a distance ed program that can work for you. Don’t forget to check that out.
Not to sound elitist, but most “online schools” are have no prestige or aren’t really worth it. If you want a certificate, there are many legit universities that will offer an online certificate.