Nobody asked for this but I made it anyway 
ROT13
Apply the ROT13 cipher to the selected text.
Description
ROT13 is used in online forums as a means of hiding spoilers, punchlines, puzzle solutions, and offensive materials from the casual glance.
As cryptii.com puts it:
ROT13 (rotate by 13 places) replaces a letter with the letter 13 letters after it in the alphabet. It has been described as the âUsenet equivalent printing an answer to a quiz upside downâ as it provides virtually no cryptographic security.
About
This is an extension for PopClip.
Author
Nick Moore
Requirements
Requires PopClip 2022.5
Acknowledgements
The cipher function is rot13-cipher (MIT License).
Changelog
25 May 2022
- Initial release
