How to start a crypto exchange mobile app development?
Could you elaborate on the key steps involved in initiating the development of a cryptocurrency exchange mobile app? I'm particularly interested in understanding the preliminary considerations, technical requirements, user interface design, security measures, and the integration of crypto wallets and trading engines. How would you recommend approaching the market research to identify user needs? Additionally, could you discuss the challenges and potential pitfalls that developers may encounter during this process, and how to mitigate them? A comprehensive overview would be immensely helpful in guiding me through this complex yet exciting journey.