A must-have app on you phone must be the app you open and quit many time every day. When you do some groceries, you need to open the app as a payment. When you have a meeting notice, you should open the app to check the time and place. When you are free, you open the app to enjoy vidoes which give you a lot of fun. When you contact your friends, you send messages to them through the app. There are actually many apps offer the services that we mentioned above. As for me, Wechat is the must-have app on my phone. Every day, From the moment I open my eyes in the morning to the time I fall asleep, I spend most time with it. Check it for over many hunderd times and make sure I don't miss any messages from others. In fact, I would feel nervous and stressed if I can't receive messages for a while. Without the app, I lost passion on other things.