The above comment (from Jan. 11, 2014, right after the last version update from Jan. 10) is only one of the comments to the Android app for the cloud service Copy, by Barracuda Networks. And the guy is right!
I’ve experienced countless cases when files were correctly uploaded via the Windows client to the Copy cloud — as the files would download just fine via a web browser –, yet the bloody Android client would corrupt the file upon download!
As the comment says, if a DOCX file is corrupt, QuickOffice would normally open what other Android office suites would reject, especially as the corruption is at the end of the file. But in the case of APK files, such a corruption makes them not installable, although 7-zip would claim they’re good archives.
By not fixing this issue for quite some time — I’ve had to deal with such random corruptions for more than a month –, Barracuda Networks showed that they’re absolutely not trustworthy. Too bad, as I had 37 GB for free with them.