His book on Alan Plater's The Beiderbecke Affair was published by the British Film Institute and Palgrave Macmillan on 28 September 2012.

[5] His journalism appears in Radio Times magazine and website, plus BBC News Online.

In March 2011 he announced on his 'Self Distract' blog that he was writing a four-part Doctor Who audio for Big Finish which is called Wirrn Isle.

Between December 2014 and July 2015, Gallagher wrote Apple-centric app reviews and other features on MacNN.com.

Since 2020 Gallagher has been uploading videos to his own YouTube channel called 58keys, where he's mainly covering writing and productivity apps for Apple devices, and giving advice to writers about how to use them.