If this plugin has helped you in any way, and you would like to return something back to make the plugin even better, there is a lot of ways to contribute:
Open a pull request containing a new feature or a bug fix, which you believe many users will benefit from. Make detailed high-quality bug reports. The difference between a bug getting fixed in 1 week vs 1 hour is in quality of the report (typically providing correct steps to reproduce that actually work). Help improve the wiki by opening a Wiki change issue, where you can improve existing descriptions, add information you found missing, fix typos / grammar mistakes or add more examples of usage of functions.