Sam Haseltine
Sam Haseltine reviewedStreaks Workout 2.0The personal trainer that you actually want to use.
 RecommendedPros: 

easy/simple, great apple watch sync (doesn't require connection to phone), accurate HR, encourages me to exercise more

Cons: 

main missing feature is addition of custom exercises - i may want to add hill/treadmill sprints to a workout, for example.

See above, plus my original comment ;)

Sam Haseltine has used this product for one week.