functions-php
There are 3 repositories under functions-php topic.
BaseMax/TopPHPFunctions
Here is the top 100 PHP functions: it is the list of the most often used PHP native functions. If you are a PHP developer, you must know the Top 100 PHP Functions deeply.
tei187/UtilitiesPHP
Some additional functions I keep using...
furkancanisci/php-functions
Some of i've created functions