Campaign Management Tools
RPG-focused campaign managers
Highly customizable. Publish "articles" for your information. Tags and cross-referencing is easy.
Includes a Digital Story Teller Screen for use during sessions.
DM worldbuilding tools as well as Player inventory tracking. Includes a handy group chat. Neat shop mechanic - DM can populate a shop with items, and the players can buy items, automatically modifying their inventories.
Currently accessible only to Patreon patrons, LK is an up-and-coming powerhouse campaign management tool.
Mixes spreadsheet sortability with wiki-esque entry editing. Great for keeping track of locations, NPCs, lore, and much more.
Your campaign gains a website, and you edit it as a website. A bit finicky, but allows lots of customization.
Powerful application for fast-and-furious note-taking with on-the-fly tagging of characters, items, locations, and more. Allows you to cross-reference your notes as you're writing them.
Contains some rules references, and handles automation of character sheet info. Can also store campaign notes.
Amazing for populating your world with NPCs. Provides a powerful Relationships tool to help you keep track.
Make a wiki for your campaign info. Player Characters can roleplay using text on a private channel.
City of Brass - Free or $5/mo
Very clean wiki-esque content creation tool.
WYSIWYG editor. Information is stored on pages that you can link to and share.
RealmWorks - $49.99
It's an older software, but it checks out!
Note-taking and organization Tools
Combines the functionality of GDocs, Evernote, GitHubWiki, Trello/Jira, and Airtable/GSheets.
Locally-hosted markdown files displayed nicely in a fresh, modern note-taking experience
EverNote - Free or $7.99/mo
Uses notebooks and tags for holding content and cross-referencing material.
A novel way to organize information, whatever that information is. Lends itself easily to DMing.
An online spreadsheet tool with fancy content capability.
$40 Windows / $45 Mac (v2.0)
Their target audience is writers. The software helps you organize stories and information, giving an organizational platform for all of your long-winded ideas.
Mind Map Tools
Flowcharts, wireframes, sticky notes, and mind maps (free for up to 4 charts, $10/month for unlimited)
Mind mapping (free up to 3 mind maps, $4.99/month for unlimited)
Associative organization tool