Developer tools
Small utilities for the decisions that come up while writing a page: a colour in the notation your stylesheet expects, a value you need to be exact. Each one is computed on the page itself, so there is nothing to install and nothing to wait for.
Utilities, not applications
These tools take no file. The input is a code, a number or a colour you type, and the answer is arithmetic on that input — which is why the page responds instantly, works the same on a phone as on a desktop, and needs no account, no queue and no export step.
The point is the value itself. You arrive with one notation and leave with whichever notation the file in front of you expects, ready to paste. Nothing to sign up for, nothing to install, and nothing left behind when you close the tab.