Jade and Reece would further collaborate on two more songs, A-side "Shake That", and follow-up single "Always", which was also co-written and produced by Levine.

Lyrically, the song reflects how during trying times Jade puts on a brave face to convince others that everything is fine, when in reality she is breaking on the inside.

"Armour" is considered one of Jade's most personal songs, and is thought to be referencing how she dealt with her late mother's passing in June 2014.

Mike Wass of music blog Idolator compared the song to various B-sides from Australian singer Kylie Minogue, calling it, "an absolute gem," and claiming, "Armour is probably the best thing the 28-year-old has released since 2012 chart-topper What You’ve Done To Me.

"[4] Due to the song's positive reception online, "Armour" was later released as a stand-alone promotional single to digital retailers and streaming services one month later on 14 August 2015.