Sites and apps similar to unpk.app include 7-Zip, which is free and open source. Other options are PeaZip, WinRAR, NanaZip and Portable Secret. File Archivers like unpk.app are a crowded field, with more than 50 alternatives for Windows, Mac, Linux, Android and iPhone.
Xarchiver is a lightweight desktop independent archive manager built with the GTK+2 toolkit. It was developed with a simple GUI which that could be used with any desktop environment and would operate using the command line rather than API calls.
p7zip is a port of the command line version of the 7-Zip file archiver to POSIX-conforming operating systems like Unix (Linux, Solaris, OpenBSD, FreeBSD, Cygwin, AIX, ...), MacOS X and also for BeOS and Amiga.
A simple software to multiple compress files and folders. ArcThemAll provides compression and extraction of batches of multiple folders or files with simple drag&drop loading. It includes an intelligent UPX compression mode, the support to self-extracting archives creation...
Italy
EU
WinArchiver is a powerful archive utility, which can open, create, and manage archive files. It supports almost all archive formats, including zip, rar, 7z, iso, and other popular formats. WinArchiver can also mount the archive to a virtual drive without extraction.
China
Info-ZIP is a set of open-source software to handle ZIP archives. It has been in circulation since 1989. It consists of 4 separately-installable packages: the Zip and UnZip command-line utilities; and WiZ and MacZip, which are graphical user interfaces for archiving programs in...
Hamster ZIP Archiver is a powerful and modern archival program that allows users to easily compress and open files from any archive.
Russia
Zipware is simple and free zip software for Microsoft Windows that supports all major archiving formats including the new RAR5 format.
ZIP Extractor is a free, open-source application for decompressing ZIP files into Google Drive.
Zipeg is a universal open source archive extractor that supports ZIP and RAR (among other archiving formats). With just a click you can open a file and see what is inside.
United States
Easily create, open and preview popular archive files like ZIP, RAR, 7z, TGZ and more ( 30+ formats supported ).
