If you’re looking for answers to study questions, or want some advice about just about anything related to study, try OpenStudy. You have to sign up if you want to participate in the conversations, but not if you just want to browse. When you visit the site for the first time, click “Get Started” → “Find more subjects” and it’ll ask you to chose a subject:
There are many other subjects, too.
Most of the questions seem to be answered pretty quickly (the site says that 75% of the questions are answered within 5 minutes). That doesn’t mean that the answers you get will necessarily be correct, but it’s one way to try to get help, and it’s also an interesting way to see how native speakers and near-native speakers talk to each other online.
Here’s an example: it’s a person asking for advice about what to write for an essay (in the English section):
There is also a free iPhone app. You do need to sign up to use it, though. I don’t see an Android app yet.