Obsidian is a must have.
Since sessions are frequently run over Discord, I use HammerTime to make sure everyone is seeing the same time being displayed.
I've been running Lancer for over a year, so all my tools are very particular in their uses. Lancer Map Creation Tool has been extremely handy in, well, creating maps and RetrogradeMinis in making up PC and NPC tokens. I also use this Pixel Art Furniture Pack for human-sized encounters, as its the only one I know that's more focused on modern aesthetics instead of vaguely medieval fantasy.
Never heard of that Map Editor before, I'll give it a look, thanks for the rec.