Also try this: lots of choices and there is a tempo app for $5.00.
I am not sure what you mean. There are a variety of services that provide music with consistent beats for fitness instructors. Muscle mixes (https://www.musclemixes.com/) has music for Silver Sneakers. These are just a few of the others: http://instructormusic.com/, http://www.move-ya.com/, powermusic.com, http://www.dynamixmusic.com/index.cfm?&gclid=CLT05LGi1LwCFW8V7AodTzMAcw,