Dropbox with plain text notes. On Android (and, I presume, iOS) it caches recently used files for offline access. If you don't access a file on your phone bef

Dropbox with plain text notes. On Android (and, I presume, iOS) it caches recently used files for offline access. If you don't access a file on your phone before going off-line it will show up in the directory listing but not actually be accessible.