This brings back the old new tab page, as much as we possibly could.

Where can I view the source of this extension?

This extension is open source and available on GitHub at https://github.com/kevin-brown/chrome-old-new-tab.

What are all of these permissions for?

Access the icons of the websites you visit. - This is needed to get the favicons of websites that will be visible in the [future] bookmarks bar and website listing. Read and modify your bookmarks - Chrome does not allow read-only access in settings, which is why this also gives the permission to modify bookmarks. This permission is needed in order to retrieve the bookmarks which will be used for the [future] bookmarks bar. Read and modify your browsing history - Once again, chrome does not allow read-only access. This is requested in order to retrieve the list of top websites you access. We do not do anything to the data other than read it. Manage your apps, extensions, and themes - The apps page allows you to manage your apps, anything from viewing the options to removing them, which is why this permission is required. This extension will only read the data for apps, along with allowing for the removal of apps through that page, which all requires user input.

Why are the thumbnails not visible on the top sites tab?

In order to generate the thumbnails on the top sites tab, Chrome requires access to a separate namespace which will generate the thumbnails. There is currently no way to grant an extension access to this page, so the thumbnails are currently defaulted to the what they would normally look like if the thumbnail could not be loaded. This may change in the future, but currently it is not possible.