f-droid.org - Enlarge ScreenshotsJS
Enlarge (and then reduce) app's screenshots by single click. Browse (i.e. next/previous) screenshots by using arrow keys, both in enlarged mode and in the normal mode.
f-droid.org - Supplemental!JS
Adds more helpful links, such as link to Google Play store and etc. inside the app's page. Adds required Android OS version and last update date of the app to top of its page. Press ' / ' to focus search. And more..
Move Gmail reply buttons to top of conversationJS
Gmail puts the "reply", "reply all" and "forward" buttons at the bottom of the conversation. This script adds buttons for these actions to the toolbar at the top of the conversation alongside the "Archive" button.