TerrariaInventoryEditor
An old Terraria Inventory Editor I once wrote for Terraria 1.3.0.8. Written with WinForms.
Quick Q/A:
Q: How to use the editor?
A: Build from source using the solution file, or run the compiled TerrariaHackGUI.exe in TerrariaHackGUI/bin/Debug/
Q: Why so many magic numbers?
A: Take a look at Terraria's source code, the whole codebase is one giant ball of magic numbers. This of course affects tools written for the game.
Q: License?
A: Zlib/png license. Check the LICENSE file.
Q: This messed up my characters / will this mess up my character?
A: Read the disclaimer popup when you launch the editor. Backup your characters. Be responsible.