The official app & game
Distributed by ApkOnline
Download this app named Urgent Caller.During your night time (or anytime) hours, the volume of the ringtone is automatically raised to the maximum after a predefined number of missed calls. Urgent Caller is simple to use and runs automatically. You never know what number will call you in the event of an emergency. This app handles them all. No need to set different ringtones for important people.
Urgent Caller from ApkOnline.net