After several years of paying £120 for a training plan application and desiring something with a less comprehensive feature set, I decided to build my own.
Run Plan is my training assistant, which displays my workout schedule, reports my completed workouts and calculates my fitness in the lead-up to a race.
In the lead-up to a big race, I define workouts in Google Sheets and import them into Google Calendar. Run Plan then pulls them in, segmenting them into weeks.
When a workout is completed and recorded with a fitness tracker, it is uploaded to Strava and displayed in the Runs section. As I accumulate workouts, Run Plan shows my overall fitness and presents it in the Stats section.