The sale is part of the daily deals email from Frog God Games, but the code (assuming it works for anyone) is: DD-HEXCH-2843 and the Hex Crawl sales page is right here. There are seven chapters to pick from in flavors of Pathfinder or Swords & Wizardry, although no print options anymore (at least not on FG's main site). These modules came out several years ago and are really exemplary for being accessible hex crawls, a great way to learn about this style of exploration play.
For newer content you'll need to go to Land of Nod and look in to what J.M. Stater is up to these days, as he's sort of the King of Hex Crawl adventures in my book, and his OSR Nod magazine is pure gold.
I admit: I picked up my copies in Pathfinder format. Thinking I might introduce my Pathfinder cronies on Saturday to Hex Crawl Chronicles.....they'll get to play Pathfinder again, and I can run some fun hex crawls that are engaging and require minimal prep on my part. Win for everyone!