Screen dimming software f.lux isn't having much luck with iOS lately, but Android progress seems to be coming along. Recently, a beta became available to interested users, likely indicating it's not too far off from a public release.
To gain access to the beta, you must have a rooted phone. Assuming you fulfill that criteria, head here to request joining the Android testing group, then here for installation instructions.
Requiring a rooted phone no doubt will alienate many users, so hopefully that gets nixed prior to the public launch. Should we hear anything to that end, we'll be sure to report it.
