The movement for the Singing Birds watches is the caliber link 1120 AT, which is based on the ultra-thin 1120. That movement was first introduced in the 1960s and, at the time, link it was the thinnest full-rotor automatic movement ever made at 2.45mm thick. Although there are thinner automatic movements today, it remains the flattest full rotor movement. It has been used by Patek Philippe and Audemars link Piguet as well.
League of Angels
Felspire
Clash of Avatars
Empire:
Tiny Mighty
Lords Road
Siegelord
Shaikan
DragonCity