Mark Moodle activity as complete from within the Activity

We are using Moodle 3.1.1 and trying to find a way to "Mark activity Complete" (via a link or button) from within each activity instead of going back to main course/topics page and checking the "Mark complete" checkbox next to each Activity. The only way I could think of is to create a custom button with same functionality as the checkboxes for "Mark complete" on course/topics page. But again should that be done as a plugin or just a custom code enhancement within Moodle? If yes, any steps in that direction would be helpful as I'm not that aware of Moodle development. Is there a simpler way to do this? Any suggestions would be really helpful. Thanks in advance!