[Updating my review, Feb 7 2020: I try to write reviews that offer constructive feedback and suggestions to the publisher, as well as helpful information for a prospective buyer. When a publisher acts on feedback and suggestions, they deserve recognition and acknowledgment, so thanks go to Eric Bright for taking reviews into consideration and making updates.]
The author states two goals: "1) I tried to make it so that NPCs can drive the plot better. 2) I made this a push-button, programmed PDF so you can get everything you need without flipping pages and rolling on tons of tables."
Back to the content...
It's all system-neutral. The good news is that you can use this across game systems. The potential hassle is that it's on you to figure out what these tables mean in your game system.
Creating an NPC
The Creating an NPC section isn't bad, but it doesn't really add anything new. For each table in that section, you can find similar content from many sources.
A couple of the tables are oriented toward a medieval European fantasy setting. The product description should mention that. If you've got cultures or species that don't fit that mold, you've got some customizing to do or you need other resources.
The tables are Job Training (200 jobs with a medieval European/fantasy flavor), Social Background (20 social categories that are mostly medieval), Economic Status (wealthy, upper class, middle class, and poverty -- nothing you couldn't think up yourself), Character Motivation, Flaws, Demeanors, and Physical Descriptions. If your game system or game setting already provides tools for generating NPCs, you might not need or want any of the tables in this section. Or maybe a table or two will fill in a gap for you.
[Updated Feb 7 2020: The term has been fixed.] By the way, in the Job Training table, someone who makes bows is a Bowyer, not a Bower (which is an attractive dwelling or retreat, or a lady's private apartment in a medieval hall or castle, or a shelter made with tree boughs or vines).
The Character Motivation table offers 60 goals for an NPC. In general, they can serve as long-term or short-term goals or drivers for the NPC. For example, "Get revenge" could be the hook for a single adventure, or it could be the driver for an NPC's years-long search for the Six-Fingered Man. This table would be a good resource if you're not already assigning goals to major NPCs.
The Character Flaw table is setting-neutral. It gives 100 adjectives describing various traits that make the NPC troublesome to those who have to deal with them. Nothing new here.
Character Demeanors gives you 300 adjectives describing the NPC's overall behavior toward others. They're a mix of positives and negatives (polite, self-centered, gentle, grumpy, etc.). Character Physical Description gives you 100 adjectives. If you want either table to give different results for different character species, classes, alignments, skills, or other elements, you'll need to customize.
Emulating an NPC
For me, the Emulating an NPC section offers more distinctive content than the Creating an NPC section. It covers two tools: Random NPC Conversations and NPC Plot Knowledge. Both tools are usable during play (if you're willing and able to make up the specifics on the fly), or you could generate some results in advance to be used if and when you need them. Either way, the results are pretty general, so you'll need to add the specifics for your game world.
Random NPC Conversations is a decent tool, especially for a more sandbox-oriented campaign. It's for when "you just want to talk to somebody and see if anything interesting comes up" (as the author says). Essentially, it generates general-purpose rumors.
First, you decide whether the NPC is normally positive, neutral, or negative. Then you roll against a table of 33 "attitudes about conversation" to see what sort of mood the NPC is in at the moment. The moods are sorted approximately from positive to negative, so you have the opportunity to come up with modifiers for the table, if you're so inclined.
[Updated Feb 7 2020: The reroll option has been turned into a specific entry. Pet peeve addressed!] Pet peeve: I'm no fan of "GM Choice or Reroll" results. My "choice" was to get random inspiration from the table. If I already had something in mind, I wouldn't have rolled on the table. If I roll on the table, I want a result.
The next step with Random NPC Conversations is to roll up the topic. You get 60 topics. Put it all together and you could find, for example, that the NPC has a "guarded" attitude about "a source of wealth" or an "insane" attitude regarding "the heritage of an NPC."
NPC Plot Knowledge is the tool I like best, because it ties the NPC to a particular adventure. It simultaneously develops a storyline and an NPC, so that's good stuff, for me.
It consists of two tables: the type of information and the topic of information. For example, you could find out that the NPC knows a) the identity of b) an enemy spy, or that the NPC knows about a) a finanical loss involving b) a beloved NPC. It's up to you to come up with the specifics. The two tables blend together well, meaning you're not going to get nonsensical combinations.
If the result is something you already had in mind, then this is your chance to share a clue. Maybe the NPC simply approaches the PCs with helpful information. Or maybe the NPC wants a favor before sharing the info. Or maybe you drop hints that this NPC knows something important, and it's up to PCs to figure out how to get the info. Maybe the NPC doesn't have the knowledge directly, but they know where you can get it.
If it's not something you already had in mind, the result can become a plot twist. When you determine that the NPC knows the identity of an enemy spy, it could be an opportunity for a big plot twist. A previously trusted or minor NPC turns out to be a spy. Or the NPC giving you this info is mistaken. Or lying.
To sum up: For me, the NPC Plot Knowledge tool is worth the one-dollar price tag on its own. None of the other tables are bad, but you'll probably want to adapt the results for your game world and your game system. For some of the tables, there's a good chance you can find similar, system-specific, or setting-specific resources elsewhere, quite possibly for free, or already included with material you've purchased.