Main idea
This is a small mod to add little features I was missing when making my adventure map.
Because of this, none of the items are actually craftable or obtainable in survival.
Features
So far this mod includes lockpicking and block pushing
Lockpicking
Adds lockpicks to allow map creators to add treasure chest like loot to their game.
Locked Barrels
Locked barrels are blocks with nine stacks of storage that can be locked. For a player to access what's inside the barrel they must use a lockpick. This unlocks the barrel and consumes the lockpick. So you better think about which barrel you want to open.
Redstone Lockable
Another block that interracts with lockpicks outputs redstone signal when locked. Using (and consuming) a lockpick on this block will turn off the redstone signal. This provides more flexibility to the map maker to make an area only accessible through lockpicking, or activating any kind of redstone contraption, command block, or anyhting else via the lockpicking system.
Skeleton Key
Inspired by TES, the skeleton key is a lockpick that never gets consumed. Infinite lockpickability!
Block Pushing
This mod also adds a block that can be pushed around for sliding block puzzles.
It is an entity that is spawned via a spawn egg and like the shulker it is physical, so the player can stand on it. Right-clicking the block pushes it away from the player. This way you can make sliding block puzzles with pressure plates or with pushing a block to an area where you can stand on it to access a higher up area.
Creative Wand
The pushable block is one block large by default, but right-clicking it with a creative wand makes it grow one block (to a 2x2, then 3x3 etc.). This way you can have a larger pushable block that can create even more interesting puzzles when trying to reach high up areas.