Nether Reactor

The Nether Reactor was a player-built structure exclusive to the Pocket Edition which, when activated, spawned large quantities of normally rare or unobtainable items. The Nether Reactor was made uncraftable in Alpha 0.12.1 and replaced with the Nether, and could only be created in older worlds that had unused nether reactors or with inventory editors.

Creation
The reactor is constructed by placing gold blocks, cobblestone, and a nether reactor core in the 3x3x3 arrangement shown below. Air blocks are required on the middle and top layers. If the structure is incorrect, attempting to activate the reactor will result in the client message "Not the correct pattern!".

Behavior
Tapping the core will activate the reactor, sending the client message "Active!" and the thunder roars. Immediately after activation, a massive 35×17×17 structure of netherrack with multiple rooms, unofficially referred to as a "Nether Spire", is spawned around the reactor. The nether reactor core turns into a block of glowing obsidian. The bottom room, which contains the reactor, replaces all blocks other than those of the reactor with air, while blocks in the upper levels remain intact.

Items will begin spawning randomly in the reactor room. These can be glowstone dust, nether quartz, cacti, sugar canes, both types of mushrooms, bowls, pumpkin seeds, and melon seeds. Zombie pigmen are also able to spawn. It is advisable to empty out one's inventory beforehand so that no items are missed, other than any weapons used to fight the zombie pigmen (unless playing in peaceful difficulty). During this stage, the blocks that make up the reactor will turn into glowing obsidian, and the core will adopt a red texture representative of being active. If the player mines the active core, all aspects of the reaction will freeze.

After 45 seconds the reactor cycle will end, causing the spire to 'blow up', leaving holes in its walls. At this point, the time is set to night. The reactor is replaced with a 3×3×3 box of obsidian containing the core, which now has a smooth, blackened texture representative of being 'burnt out'. If the player builds a new reactor around the burnt out core, the spire will generate, it will be stuck at night, but no other behaviors associated with the reactor will occur. Because of this, netherrack is renewable.

The reactor cannot be activated in Creative mode.

Conditions

 * All players must be within the spire's area
 * The reactor must be built at least 32 blocks below cloud level, or 4 blocks above the void
 * The player must be standing level with the reactor

Trivia

 * The spire is composed of over 25 stacks worth of netherrack.
 * Excluding the core, any part of the reactor can be mined after activation and it will still function. This way, the player can recycle the expensive gold blocks. If they're fast enough, they'll have time to mine all four gold blocks before they turn to glowing obsidian.
 * Because the spire cannot replace blocks past the world border, when the reactor is activated near the edge of old worlds the player will be able to see the time set to night.
 * If the nether reactor core is mined out while the nether reactor is active, the glowing obsidian will not turn into obsidian after the reactor deactivates. This also causes the reactor to stop spawning items and zombie pigmen.
 * On 0.15.0 the texture for this block was changed.