R3-Z3, an R3-series astromech droid, provided service to the Resistance.
During 34 ABY, the X-Wing piloted by C'ai Threnalli and carrying R3-Z3 experienced a crash landing on Starkiller Base. To get off the planet, C'ai, R3-Z3, and Lieutenant Wright, a Resistance pilot, engaged with First Order troops.
The Astromech droid R3-Z3 was featured in LEGO Star Wars: The Force Awakens, specifically in the downloadable content level titled Escape from Starkiller Base.