If you know Laravel, you'll know that it has a built-in REPL called Tinker
that allows you to interact with your entire Laravel application on the command line. Tinkerwell
brings tinker out of the command line and gives you a full-blown UI to work with, as well as adding a tonne of other functionality.
Tinkerwell has been a game-changer for me since I discovered it. It lets me develop chunks of code while testing them in isolation, inspect data structures at run time as an interactive table, and easily run one-off pieces of arbitrary code on any environment (instead of creating custom commands for them).
It's not just for Laravel either. Tinkerwell can run any PHP code and includes framework support for Symfony, Statamic, and WordPress, among others. Well worth checking out.