I only found out that the impressive big project often too intimidating to finish, so when I'm free from work, I tend to gather small samples, hope they can become a part of my super awesome big project one day. So here are all my collections, I'll try my best to keep it tidy, although it's very hardXD, feel free to share and give me adivse to yushunchn@gmail.com!
-Notifcations, notfication before API 26 without channelID
-Notifactions2, basic notfication usage API>=26