What are the best bitcoin apps?

Could you please elaborate on what you consider to be the criteria for the "best" Bitcoin apps? Are you looking for apps that offer a seamless user experience, a wide range of features, or perhaps those that prioritize security above all else? Additionally, are there any specific functionalities you're seeking, such as the ability to buy and sell Bitcoin directly from the app, or to track your holdings in real-time? Knowing these details would help me provide a more accurate and targeted response to your question.