This mod does nothing more than read whitelist-style files from one or more remote sources and add those players to the Headcrumbs players (heads as well as mobs). It'll update automatically in specified intervals if configured to do so. By default data is cached for 24 hours.

It can be used with services like http://whitelist.twitchapps.com to get your Twitch subscribers into your game, but it can basically read from any file located somewhere on the internet. Each line in said file has to contain one username, similar to how whitelists were handled prior to the change to UUIDs.

Update: whitelist.twitchapps.com is no longer available.  I'll be looking into adding support for other whitelisting services. If you just want to mock up a file for the time being, it could look like this:

blay09
xXMinecraftDestroyerXx
jeb_

Just one name per line. 

How to use:

Head over to the twitchcrumbs.cfg config file and add your whitelist source(s) to the list as shown in the example below.