Chrome DevTools REPL for ClojureScript version 1.5.1 is now released to Chrome Store. It's biggest new feature is ability to inject cljs.core into pages not containing it. It means that it is possible to use REPL against pages which were not developed in ClojureScript.
PS
it may take up to 60 minutes for the update to become available
PS
it may take up to 60 minutes for the update to become available