Free icons for any object in the world
These CC Attribution licenses always scare me off. First off, what the heck does this even mean?    You must attribute the work in the manner specified by the author

The author almost never specifies how they want to be attributed.  But since they're using an Attribution license they must want to be attributed some how.So how am I going to attribute an author if I'm using their icons in a mobile app?  That seems like quite a bit of extra work.I don't want to sound unappreciative, this is an awesome project, but I need a "how to use CC attribution art for dummies".