Quad Adder is a simple tool for adding new quad face at boundary.

It can be used for curvy mesh surface for both modeling new object or repairing.

When used with tools like LoopTool, it can create smooth surface easily. Also it has a simple rotation setting and balanced face direction (for curvy surface).

Usage

Go to blender Edit mode, switch to Edge mode,

select 1 or 2 edges at the boundary, when right click inside the 3d viewport,

then select Quad Adder at the bottom of the pop up context menu of blender.

This is a free addon ! Hope that you like it : )

https://x.com/kushirosea