Just to add I've also been asked about adding this functionality for the Command-line app as well (although I'm not 100% sure how it'd work). It would definitely make sense to have a common 'Storage' API in EspruinoTools for listing/reading/writing and that's something I could add quite easily.
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.
Just to add I've also been asked about adding this functionality for the Command-line app as well (although I'm not 100% sure how it'd work). It would definitely make sense to have a common 'Storage' API in EspruinoTools for listing/reading/writing and that's something I could add quite easily.