This chapter reviews the integration of technology in out-of-school settings targeting mathematics education, providing a comprehensive analysis of both opportunities and challenges in this evolving educational landscape. We begin with a thorough examination of the advantages and limitations of technology implementation in mathematics education, offering insights from global perspectives while specifically highlighting the Turkish educational context. We then investigate how technology shapes mathematical learning beyond traditional classroom boundaries and informs analyses about impacts on student engagement and understanding. To that end, we build on previous studies through an extensive literature review of technology integration into informal mathematics learning environments, identifying trends, successful implementation strategies, and persistent challenges. We then zero in on the Turkish educational system, providing valuable insights into both policy frameworks and practical applications in a specific national context. We also present three innovative case studies of technology-based mathematical activities that demonstrate some practical applications of technology in out-of-school mathematics learning. These activities provide specific examples of how technology can serve as a bridge between formal and informal learning environments while making the mathematics more accessible and interesting to students and leading to deep mathematical learning. We conclude that while technology has huge potential to enhance mathematics learning out of school, successful implementation requires a carefully considered pedagogical approach, technological infrastructure, and the needs of the students.