Military applications 

Barium nitrate is also used in flares and fireworks, also as an igniting agent often for other flammable materials. It's used in many flares used by the military, like the MK58 naval flare pictured below used in the rescue. This used barium nitrate as the igniting element of a white phosphorus burning agent. The Seasprite SH2 used in the rescue always carried 8 of the flare canisters, fired from front-mounted ejectors. They were used for marking locations in search and rescue, anti-submarine warfare to mark submarine locations, and used hovering practices as a visual marker among other uses. 

It can be combined with thermite to make Thermate-TH3, the material used in Thermite grenades by the military, as well as a tracer and incendiary rounds.  Barium nitrate mixed with aluminum powder also forms flash powder, a highly explosive material used as an igniting agent in some bombs.