We do not have a download file for the latest version (1.5.7.18), but you can try downloading it from the developer's site
Download version 1.4.1.18 from Mac Informer
Version: 1.4.1.18
Date update: Aug 11, 2014
File name: manaplus-lion-1.4.1.18.dmg
Size: 15.6 MB