Bukkit

This plugin adds many special features for spawners. It enables players to upgrade their spawner to a configurable amount of configurable levels, play special effects around spawners, change mob types and more.

This plugin soft depends on Holographic Displays. Having the compatible version of it combined with this plugin will give you some cool extra features, such as showing the spawn delay above a spawner, and more!

• Upgradable spawners. Configure the amount of levels, and configure each level individually.
• Right click a spawner to open it's menu. Upgrade it, change it's type or edit the settings of a spawner.
• Play configurable effects around spawners (you can set different effects for each defined level).
• Show the remaining delay above a spawner. (requires Holographic Displays to be installed)
• Change a spawner's type in the menu, with a command or with right clicking with a spawner egg.
• Enable or disable  a spawner.
• Lock a spawner to only allow it's owner to edit it's settings or removing the spawner. (untested)
• An in-game command to manage the plugin and spawners.

If you have any suggestions for features that could be added, please create a ticket on the Issues page. Thank you! 

I've set up a Patreon page for anyone willing to support me. Supporting me there will include special rewards. But do know, using my plugins is enough support, so no need to push yourself into pledging to the page. You can also make a one-time donation at Ko-Fi.