You are free and welcome to share your themes on this section (see more info in the FAQ)
To install a theme just unzip its content to the XKeyBrew/app/themes folder and refresh the theme list.

XKeyBrew (bundled with the app)

XKeyBrew Light (bundled with the app)

Ayala Gray (by Ayala) (bundled with the app)

Ayala Pink (by Ayala) (bundled with the app)

City (by Koala0145) (bundled with the app)

W8 (by Koala0145) (bundled with the app)

Halo 4 (by Jopa87) (bundled with the app)

Avenged Sevenfold (by Avenged Sevenfold) (User Created)

Download:[https://bitbucket.org/AvengedSevenfold/a7x/downloads/Avenged%20Sevenfold.rar]

GreenDarkness v1.0 (byReloxX) (User Created)

Download:[https://bitbucket.org/reloxx/xkey-themes/downloads/GreenDarkness_V1_0.rar]

Shelves (by itsmeee) (User Created)

Download:[https://bitbucket.org/itsmeee/snrep/downloads/Shelves.zip]