[metadat]

You might like Tamper monkey. You can add a button to kick it off or whatever your heart desires.

Tampermoney also works around CORs issues with relative ease.

[crtasm]

Userscripts for the win. Consider Violentmonkey over Tampermonkey though.

[metadat]

> Consider Violentmonkey over Tampermonkey though.

Why?

[MC995]

Probably because it looks to be closed source these days.

https://github.com/Tampermonkey/tampermonkey

> This repository contains the source of the Tampermonkey extension up to version 2.9. All newer versions are distributed under a proprietary license.

[panphora]

Open source

[joshdavham]

I love Tamper monkey! I've never made my own scripts though - just used other peoples'.