Show HN Karma is an userscript which appends the karma of HN users after their names.
Installing the userscript
1. Install an extension in your browser which lets you use userscripts:
|Safari (not for iOS)||Tampermonkey|
If you're using Firefox, you have to restart it to finish installing Greasemonkey so do it before you jump to the next step.
2. Click Show HN Karma and install the userscript.
3. Load/reload Hacker News, you will now see the karma after usernames.