After surviving a life-changing explosion in Afghanistan in 2011, JJ has won athletics medals for his country, befriended royals and is now a popular broadcaster.
The athlete, TV personality and former Marine Commando is the eighth celebrity confirmed for the new series.
The pair got behind the mic at Abbey Road Studios as a charity single was recorded for Harry's Invictus Games Foundation.
The Duke of Sussex also spoke about his new son, Archie Harrison.
Prince Harry is launching the one year countdown to the Invictus Games in the Netherlands. His visit comes days after the birth of his son with Meghan, Duchess of Sussex. The couple have named their son Archie Harrison Mountbatten-Windsor.
A royal source said Prince Harry is encouraging Meghan to "pace herself".
Prince Harry might be on his honeymoon, but that doesn't mean the royal has stopped thinking about work.
In amputating my leg, doctors accidentally tampered with my treasured Liverpool tattoo. It now read: 'You'll Never Walk'
We were on our way back into camp, where we were due to have two days R&R because it was Christmas when I stood on and detonated an Improvised Explosive Device