At present, the mainstream mainly includes online travel agents such as Ctrip, Tongcheng, Qunar, Youyou.com app (affiliated to CYTS) and Donkey Mama, or apps with the nature of raiders. I did some research when I was doing my thesis, and now I still recommend Ctrip and where to go. The function is relatively complete, the interface is clear, and the website traffic is relatively large (indicating that there are many users). You can choose one according to your preference.