In wordpress , there are several plugins are available for different job. Suppose you have to write a plugin for multiple jobs. These respective plugins are also available. Then simply you can attach third party plugin into your plugin.
At first find the below code for the third party plugin which you want to include into your own plugin.
/* Plugin Name: Plugin URI: Description: Version: Author: Author URI: License: */
STEP 1: Remove the commented section from the downloaded plugin.
STEP 2: Copy the downloaded plugin into your plugin folder.
STEP 3: Then include the page which you removed the commented section.