SmiRing is a free Android application developed by Shigeo Matsu that helps to calm babies down and stop them from crying with various baby-stop-crying sounds. It is a perfect solution for parents who struggle to soothe their babies when they are fussy or crying at night.

The app features twelve different sounds including plastic bag, TV, dryer, vacuum cleaner, tap water, underwater, noodle, toy, heartbeat, laugh, rain, and drum. The sounds can be played simultaneously, allowing parents to try various combinations to find the best one that works for their baby. Additionally, the app comes with a timer function that lets users set the duration for playing the sounds.

SmiRing also has recording and playback functions that enable parents to play their voices or songs repeatedly. Overall, SmiRing is an excellent app for parents who want to calm their babies down and get them to sleep peacefully.