The Recycle Tool is replacement for Trash Tool that is given by default to players. Instead of trashing an item it gives player random amount of gems based on rarity, just like breaking block with hand, or if the item can be bought from the store, it gives 10% the price that was used to buy it from there. For example, World Lock costs 2000 gems in store but if recycled it gives only 200 gems.
It can be obtained by earning the Supporter status, either by earning 7,000 Gems through Tapjoy (a mobile advertising and monetization platform), or by making one In-App Purchase
Easter egg added by devs when trying to recycle negative number of items
World Lock recycling example showing it gives only 10% from original price
The message displayed when one tries to recycle a partial amount of fish.