I wanted to compile a list of free resources you can use when you run Old School Essentials on FG. I am going to try to highlight some that people may not know about. These are the ones that I use. If you know of others post below and I can add them.

Theme
Although any Smiteworks theme should work* This is my favorite.

https://forge.fantasygrounds.com/shop/items/388/view - by psicodelix

Utilities

https://forge.fantasygrounds.com/shop/items/321/view - Old School Essentials- Convert 2e Monsters to OSE by Bayne
Use this extension to convert STORE purchased D&D Classics modules to OSE. it converts the encounter and/or NPCs.

https://forge.fantasygrounds.com/shop/items/212/view - Clear Dead by Matt Kure
Quickly clear dead unfriendly NPCs

https://forge.fantasygrounds.com/shop/items/518/view - Cohorts and Companions by MostTornBrain and MeAndUnique
Lets you drag a NPC to your character sheet and then to Combat Tracker. Allows the player to fully control the NPC.

https://forge.fantasygrounds.com/shop/items/565/view - FGTabber2 by jharp
Lets you setup tabs inside Fantasy grounds. Its amazing for organizing your game as a GM.