This app was mentioned in 1 comment, with an average of 2.00 upvotes
Meditation Timer on Android. I know, real creative name. But it's great. Has optional background sounds, can sound multiple alarms, the alarm bell will sound a pre-defined number of times. Lots of options. Completely free.
https://play.google.com/store/apps/details?id=com.dhintz.meditationtimer