A broad selection of apps is theoretically great, but in reality there are entire genres of apps worth skipping on Blu-ray players. Sure, you could find that out the hard way by trial-and-error, but that's particularly frustrating on Blu-ray players where you often have to tediously enter in a log-in and password using an onscreen keyboard and a remote.
The big-screen experience just doesn't lend itself to all types of apps, so here's a quick cheat sheet of apps you can pass over.
Twitter on your TV? Not worth it. The social experience always feels clumsy on the big screen and you're better off checking out those services on a laptop, tablet, or smartphone--like you're probably already doing.
Casual gaming is great a time-waster on your phone, but it's boring on an HDTV. Take all the worst aspects of casual gaming (repetitive, simplistic gameplay) and combine it with a terrible controller (a Blu-ray player remote) and that's the experience of Blu-ray player gaming.
Reading headlines and article summaries from several feet away on the couch just isn't compelling content. That's been our experience with most news apps, plus the experience always feels much slower than browsing news on a laptop, tablet, or smartphone. Even the news apps that offer video are typically limited to short, Internet-video-quality clips that don't look good blown up on an HDTV.
Once you rule out those categories, you're pretty much left with the good stuff: streaming-video, music, and photos. That might seem boring if you're used to the huge variety of cool apps available on smartphones and tablets, but exploring different apps almost never pays off on Blu-ray players.
Know of a Blu-ray player app that defies these recommendations? List it in the comments.