Which One Direction member released a solo album titled 'Flicker'?

Niall Horan released the solo album Flicker.

Flicker was Horan’s debut solo studio album after his time in One Direction. Capitol Records released it on 20 October 2017, beginning a solo career that developed a softer blend of folk, folk-pop, country and classic-rock influences. Horan cited artists such as Fleetwood Mac and the Eagles as inspirations for the album’s guitar-led sound.

The album’s lead single, “This Town,” arrived in September 2016, before “Slow Hands,” “Too Much to Ask” and “On the Loose.” “Seeing Blind,” featuring Maren Morris, was another notable track. Horan said the title song, “Flicker,” was especially important to him and influenced how he approached the rest of the recording.

Flicker debuted at number one on the US Billboard 200 with 152,000 album-equivalent units. Horan was the third One Direction member to achieve a solo US number-one album, following Zayn Malik and Harry Styles.