If command line is enough, there is already unzip in the Touchpad.
It is part of webOS (part of BusyBox) although the one available under Preware might have some enhancements.
BusyBox v1.17.3 () multi-call binary.
Usage: unzip [-opts[modifiers]] FILE[.zip] [LIST] [-x XLIST] [-d DIR]
Extract files from ZIP archives
-l List archive contents (with -q for short form)
-n Never overwrite files (default)
-p Send output to stdout
-x XLST Exclude these files
-d DIR Extract files into DIR