Lusus Naturae is a monster book for Lamentations of the Flame Princess, though you could use it with pretty much any OSR type game without a lot of fuss. LN is filled with fucked up monsters that make absolutely no sense and completely own it. Many of them are cool, but some get kind of samey. Ah, another four legged centipede thing with vaginas for eyes and if you kill it the campaign world ends. Don't get me wrong, it's good, but I can only do so many variations on the Abstract Unrelenting Horror thing before I start getting a bit numb to it. The monsters in this book are, IMO, best used sparingly in a campaign where most of the antagonists are humans or animals. A good portion of the monsters are unique entities. For the present price of $6.66 (yes, we see what you did there) it's a good buy.
The Starship From Hell is a delightful system-neutral generator that gives you the classic "starship in distress," with a lot of damned interesting premises. It's very Lamentations-flavored and has some implied setting details, (most of which point to a baroque and fairly awful universe) but with a little replacement of proper nouns you could drop this mofo into Stars Without Number, X-Plorers... hell, you could rock any non-OSR sci-fi game with this. It's actually my favorite of the three downloads today and is presently Free Ninety-Nine, if you know what I'm saying.
ViewScream is a live action RPG meant to be played over Hangouts or Skype or something where you can see the other players as faces on a view screen. I'm actually not so much interested in playing or running this as I am in studying it. It's presently free because Mister Chandler is working on a second edition.
I dig on Chandler. His stuff is crazy gross metal, so if you're not really into that, his work probably isn't your jam. However, his work is clever and visceral and it isn't schlock for the sake of schlock.
This stuff isn't my first Chandler rodeo. I also have No Salvation for Witches (a module he wrote for LotFP) and Pandemonio. (A squicky horror/action game using only d12s!)
On a totally unrelated note, my Middle Eastern-flavored 5th edition game continues on Friday, with the party exploring the abandoned (?) ruins of the poisoners' guild hideout north of Agrama.