Anitya Alternatives
Anitya is described as 'A software release monitoring project' and is an website. There are three alternatives to Anitya, not only websites but also apps for Linux. The best alternative is Repology, which is both free and Open Source. Other great sites and apps similar to Anitya are pkgs.org and whohas.
Repology, the packaging hub Repology monitors a huge number of package repositories and other sources comparing packages versions across them and gathering other information.
Features
The pkgs.org is created to provide you with the simplest method of searching and downloading the newest versions of the Linux packages without the usual excessive popups or spyware.
whohas is a command line tool that allows querying several package lists at once - currently supported are Arch, Debian, Fedora, Gentoo, Mandriva, openSUSE, Slackware (and linuxpackages.net), Source Mage, Ubuntu, FreeBSD, NetBSD, OpenBSD, Fink, MacPorts and Cygwin.