This list includes items that aren’t full VTTs but can be used to support what you already use
For full VTTs look in VTT database
Discord
DnDBeyond
Battlemaps with synced movement/changes
Voice and Video Apps
Character Sheet Apps
Online Dice Rollers
Rules Reference
Turn Tracking
Handouts, Visual Aides, and Collaboration
Scheduling and Looking for Games
Other GM Resources