The Chinese has a very systematic and complex family relationship (a.k.a. kinship) terminology system which maintains a separate designation for almost every one of ego's kin based on their generation, gender, lineage, relative age, etc.
Do you know the Chinese family designation of each and everyone of your relatives? I've found an interesting Android app by chance, which can help you to quickly find out the correct designation. So, no more embarrassment in calling your relatives correctly when you meet with them next time during family gathering, wedding dinner, Chinese New Year visiting, etc.
The app is called My Relatives (亲戚关系) and you can get it from https://play.google.com/store/apps/details?id=com.lanhk.myrelatives.