As you may know, Lollypop is an open-source, audio player developed in GTK+3, created as a Rhythmbox alternative. Among others, it has support the playback of the most popular audio formats, including mp3, mp4, ogg and flac, allows the users to visualize the songs via album, artist or genre, can play the files in order or shuffle (random).

It has two UIs, a while one and and a dark one, making the player fit with many designs and interfaces.
The latest version available is Lollypop 0.9.87, which has been recently released, coming with bug-fixes only.
Installation instructions:
Lollypop can be installed easily on a lot of systems, since it is available via either PPA or repository.
How to install Lollypop on Ubuntu 16.04 Xenial Xerus and Ubuntu 15.10 Wily Werewolf systems:
$ sudo add-apt-repository ppa:gnumdk/lollypop
$ sudo apt-get update
$ sudo apt-get install lollypop
For Unity only, disable the overlay scrollbars:
$ gsettings set com.canonical.desktop.interface scrollbar-mode normal
Optional, to remove lollypop, do:
$ sudo apt-get remove lollypop
How to install Lollypop on OpenSUSE 13.2 and derivative systems:
$ sudo wget http://download.opensuse.org/repositories/home:/gnumdk31/openSUSE_13.2/home:gnumdk31.repo -O /etc/zypp/repos.d/home:gnumdk31.repo
$ sudo zypper refresh
$ sudo zypper install lollypop
Optional, to remove lollypop, do:
$ sudo zypper remove lollypop
How to install Lollypop on Fedora 22 and derivative systems:
$ sudo yum install dnf-plugin-copr
$ sudo dnf copr enable gnumdk/lollypop
$ sudo dnf install lollypop
Optional, to remove lollypop, do:
$ sudo yum remove lollypop
How to install Lollypop on Arch Linux and derivative systems:
$ sudo yaourt lollypop
Optional, to remove lollypop, do:
$ sudo yaourt -Rsn lollypop