Roblox Developer Tools
Free Tools
Design
Blender - 3D Modeling + Rendering and animation.
Blockbench - Low Poly 3D Modeling (with minecraft exporting capabilities)
Coding
Wally - The Roblox Dev's package manager.
Rojo - Visual Studio Code Roblox Dev. implementation.
^^^ Also check out their docs! Plenty of good recomandations.
VS Code Extensions
Roblox API Explorer - Explore latest Roblox API with ease!