I had the same problem. In order to make my part of apps.json correct, I had to change spacing after colons, despite a variety of spacings in the examples already present. What my mistake was, I don't know. But finally the upload went through.
Espruino is a JavaScript interpreter for low-power Microcontrollers. This site is both a support community for Espruino and a place to share what you are working on.
I had the same problem. In order to make my part of apps.json correct, I had to change spacing after colons, despite a variety of spacings in the examples already present. What my mistake was, I don't know. But finally the upload went through.