Hang Glider
mt-mods

Adds a functional hang glider for exploring

Nether
PilzAdam

Adds a deep underground realm with different mapgen that you can reach with obsidian portals.

Boost Cart
Krock

This mod offers improved minecarts and a few more rail types.

Gadgets Modpack
mt-mods

A modpack providing full progression of magic and technology-based items that apply status effects or do other useful functions