Ask Slashdot: Best Phone Apps?

An anonymous reader writes: The phone app ecosystem has matured nicely over the past several years. There are apps for just about everything I need to do on my phone. But I've noticed that once an app fills a particular need, I don't tend to look for newer or potentially better apps that would replace it. In a lot of areas, I'm two or three years out of date — maybe there's something better, maybe not. Since few people relish the thought of installing, testing, and uninstalling literally hundreds of apps, I thought I'd put the question to the Slashdot community: what interesting, useful new(ish) apps are you aware of? This can be anything from incredibly slick, well-designed single purpose apps to powerful multi-function apps to entertainment-oriented apps.