jar converter freeware downloads
Conversion Amanuensis
5.5 freeware download... adjusting as necessary to account for where the jar file is. You can run it online at mindprod.com/applet/converter.html without installing it. ...
PeaZip Portable
9.7.1 freeware download... thumbnail viewer, verify hash, find duplicate files, file converter eg. rar to zip...), especially focused on security: strong encryption (AES, Serpent, Twofish), two factor authentication, ...