Streaks helps me not forget any parts of my daily routines and habits; i use it to make sure i don’t skip more than one day between workouts, to make sure i do my morning journals, and for keeping track of water intake.
someone recommended Things in the past, and i’d say i use the two apps pretty effectively together… Streaks gives me nice feedback about how long i’ve been keeping a streak going, longest streaks, etc; where Things is really useful for one off tasks or larger projects.