Here are some tools and small demonstrations I have made in the past.

Map Planner

This is a graph storage format intended to assist with developing games with a large number of areas. (As my games tend to have) A small CLI to interact with the format may be found here.

Virtual To-Do List

This is a minimalist tool made for a friend. It allows you to create "tasks" which you can then click on to mark them as "complete."
It remembers your tasks, and will automatically un-complete them daily for you. It may be found here, however if you plan on seriously using it for organization, I would just bookmark it.

These tools are made specifically for use by Minecraft and/or DiamondFire. Any "Recode" buttons will automatically send relevant items or information to the client using the Minecraft Recode mod.

Minecraft Lore Image Generator

This tool generates a Minecraft command to give an item with an image as its lore. It may be found here.

Minecraft Skin Icon Generator

This tool generates a front-facing icon from your skin's texture file. This may be used for icons, profile pictures, etc. It may be found here.

DiamondFire Template Encoder/Decoder

This tool encodes or decodes code templates from DiamondFire. It may be found here.

DiamondFire Object Notation

This is technically one of my languages, however it's relevant for this section. DFON is very similar to JSON in syntax. It is intended to be a way for DiamondFire plots to easily represent and compile constant data. The documentation and compiler may be found here.