D&D Beyond - Official online toolset for Dungeons & Dragons tabletop gaming
Roll20 - Roll20 is a suite of easy-to-use digital tools that expand pen-and-paper gameplay.
Talespire - TaleSpire is an online, digital, graphical way of playing classic P&P Role-playing games with...
Astral Tabletop - Create, host, and manage your tabletop role-playing games — online or in person
Adventurer's Codex - A free, easy to use, in-person D&D 5e gaming system for characters, campaigns, and parties.
Dungeon Masters Vault - Extensive tool set for D&D 5e dungeon masters.