Cache question re: Calibre Library Android app

[martyh]

Hello,

Regarding the Calibre Library android app:

I've emailed the developer twice in as many weeks but have received no response; I posted this question to the Calibre Library forum, but have received no response --

So I'm hoping someone here can help me out:

I have the Calibre Library app installed on my N7. With File Explorer ES I found that the "cache" folder for this app contained dozens of files all in the format "-21449....." Does anyone know what these files are? What creates them and/or can they be deleted?

I've only used Calibre Library twice to wifi a couple ebooks from my PC to the N7, so all these cache files cannot be caused by the two ebooks.

Any help would be most appreciated.
Cheers,
- mh