Just the dialog box with $1 should suffice. I do this on Windows. I can copy it to whichever appropriate browser, or simply dismiss it. I have my terrible source code somewhere on the Internet, but it should take less than couple femtoseconds for any HN readers to write their own, I suppose. I recommend everyone do this.

I have considered doing exactly this on many occasions but have never gotten around to putting it together - though I hadn't considered using Zenity.

I think a polished packaged cross platform app that does this would have some audience -akin to the intent dialogues on android & ios.