BroadwayWorld.com This app will keep you in the loop and up to date on all the latest news on everything from broadway, to off broadway, to regional shows. It's a handy little reference.
tkts The one thing I hate about broadway is that it's seriously expensive. But TKTS eases the sticker shock with often deep discounts to awesome shows. Case in point: I saw a wednesday evening performance of "American Idiot" with Billy Joel Armstrong from the 8th row for a little over $60. Awesome.
Playwright Quotes Let's take a moment to appreciate the wordsmiths without whom no theater would be possible. I love this quote generator because, unsurprisingly, playwrights tend to have some pretty interesting things to say.