I love your maps! I'm flight crew and I use them all and a lot! Always recommend them to my coworkers. In China I'm missing chengdu, hangzhou and Xiamen though.
KLM offers a direct flight too Xiamen from europe and it's a popular holiday destination for local chinese too and there is currently no alternative metro app for this city on google play. It desperately needs one. please consider doing Xiamen! Thank you.