A collection of small add-ons to make it easier to use Blender as an old-school-ish level editor.
Decrease/increase grid scale manually and simultaneously for all viewports, using Numpad -/+. Reset the scale using Numpad *. When you change the grid scale it will be output to the bottom header. You can set a custom grid scale multiplier and a custom unit name in the add-on preferences (you might want one unit to equal 32 pixels, for example).
Important! Use the "None" unit system.
Extrudes a selection of faces into a split and closed mesh, using Ctr+Alt+E.
Assigns the selected material in the Asset Browser to your selection. Re-uses materials and material slots when possible. It's currently not possible to hook into the Asset Browser's drag and drop functionality, hence the button (if you know how to make asset drag-and-drop work in Edit mode, let me know!).
Blender has a crucial setting called "Correct Face Attributes", which prevents UV distortion when you're manipulating a mesh.
Jason van Gumster's Lockview script that exposes the lock view rotation that Blender's Quad View uses. This lets you set up and lock custom orto viewports.
https://gist.github.com/Fweeb/bb61c15139bff338cb17
Bram Eulaers' wonderful DreamUV that lets you do a lot of UV related stuff in the 3D viewport.
https://github.com/leukbaars/DreamUV
This add-on gives you a toggle to double-click to link select.