From version 4.9 onwards, the icons shown on the page can be removed by choosing "Do Not Show Icons" option from the Options page. If you choose to do so the scrolling capabilities can be handled by toolbar button or via the context menu entries (right click menu).
This is for someone who does not want the icon to cover useful area on the page.
In terms of future path of this extension, it also has a benefit in terms of privacy as doing this will require less permissions in future releases of Scroll To Top.
Since privacy is a growing concern, I believe applications and tools should start with minimum and less greedy permissions and can request permissions later when it is requested by the user.
This can be achieved by using activeTab permission in this case. You can read more about Chrome proposed solution here and more about activeTab permission here.
Currently Scroll To Top extension requires <all_urls> permission to load the icon on every page, this grants the extension to render the icons on all eligible pages. As a software programmer myself, this is too much to ask but unfortunately there is no other way to render the icon without having this broad permission.
One proposal that I've in my mind is to declare this greedy permission as optional and show toolbar button and context menu as default interaction UI. If user wants they can grant other permission so that the extension will behave how they have seen it so far, which places icons on the webpage.
In future once I release the extension with minimum permission, you might see some changes where I'll by default activate "Do Not Show Icons" and remove <all_url> permission from this extension.
Once you want to switch back to old style of having icons on the page you can then do that by switching the option. While switching to show icons it will require your permission and a popup will be displayed to you.
Scroll To Top extension is an open source project hosted on GitHub repository.
You can follow @scrolltotop on Twitter.
In the end, I just want to thank you all for using this extension and appreciating this. I want to be completely transparent with my users. Suggestions are welcome.