Simple text tools

The two I keep looking for online are:

• Base 64 encode/decode
• JSON format (validity check)

Browsers can do both locally, so MVP is a text area with buttons for each command.

Put the result in a new copy of the text area, with its own buttons, so chaining operations is easier.

Post MVP:

• Copy to clipboard

• Hook into fetcher (for logged in users at least)

• JPath/jq stuff

  ("Download this url, extract these parts of the doc, print the output, or use it as the body for another request")

• Date maths ("today plus two weeks")