Extending your plugin options

Hello, i would like to extend your plugin by adding some new input field options to your existing ones.
I created a plugin for the purpose, but I cannot add my options into your plugin options page. He result is I have two menu items under Settings: Post Views Counter (yours) and the plugin extension (mine). I would like to merge theme.
Could you gentle address on that, if possible?

Thank you.
Riccardo.