Random Tool Kit doesn't have an overarching theme, it's just a collection of useful tools. It features various items to help manage your tools, build and get around easier. It also has a a variety of inflatable tents for explorers, including a tent which can be deployed on the bottom of the ocean and a magic tent which retains its interior when picked up (the Ender Tent). See more here.
This mod may be used in modpacks without restriction.
Thanks to ACGaming for providing German translations!