I haven't seen the new site design but it seems ok. When I started learning the guitar (~6 years ago) Justin was a huge help but I complemented that with in person lessons with some teachers and with additional material/random songs. So consider me a fan. I also recommend getting in touch with other musicians/players, that's gonna push your level way more than an app would.
May I ask how long ago you've started learning and what level are you at?
I think there is a lot of great material online. But in order to grok most of it you need to have some foundation.
I've never used any app (well, I use a metronome app) since I haven't seen anything that looked useful. Ear training apps could be useful but I haven't been able to stick with it. In general "apps" seem a poor fit for teaching the guitar.