Both websites for developer doesn't appear to be working. Getting an unusual error message for updates. "You have updates available for other accounts. Sign in to acct you used to purchase it". In other words all my apps have been updated, but still get this error. (catch 22?)
Hmmm, there are already a lot of such apps available, many that are better featured, i.e. they allow viewing the archived files before extracting, e.g.: BetterZip and Zipeg. Even looking at the pro-version at the developer's site, it doesn't appear this feature is available
Also, the Apple Store reviews have a very curious bimodal distribution of one- and five-star reviews, with the former reviewers saying the app doesn't work.