Tools

Unreal Engine (Uasset Viewer/Editor)
GitHub - kaiheilos/Utilities

UAssetGui (Uasset Viewer/Editor) Recommended!
GitHub - atenfyr/UAssetGUI: A work-in-progress .NET GUI to facilitate reading and modifying Unreal Engine 4 game assets.

uModel (asset viewer and exporter)
Gildor's Homepage

FModel (Software for exploring Unreal Engine games) Easy to use
Home Page

Blender (importing and rigging models)
blender.org - Home of the Blender project - Free and Open 3D Creation Software

Plugin to import .PSK files into Blender
Blender PSK plugin

Unreal Engine project template (with alpha materials by Amoory)
SIFU Content Template

UnrealPak
UnrealPak

Character model templates for rigging

 * Female protagonist .blend file
 * Male protagonist .blend file