App recs for advanced marathon training - London 2026

Hi! I’m running the London Marathon and plan to start training at the end of December. I’m a run coach myself, but I don’t want to work 1:1 with a coach this time around. I’ve done custom coaching before and followed Pete Pfitzinger’s Advanced Marathoning plans, so I’m comfortable managing the work, just looking for an app that provides solid structure and flexibility.

Right now I’m eyeing Runna, Hal Higdon, and Nike Run Club. Ideally, I want something that’s:

• geared toward more experienced runners
• easy to tweak mileage or move workouts around
• integrates cleanly with Garlin

Anyone here used these (or others) for a marathon training cycle? Curious what’s worked best for you!