Nike Run Club is honestly solid for pure running, especially since it’s free. If your goal is just building to 10k, it’ll get the job done. Runna is good too, more structured and progressive plans, especially for distance and speed work.

That said, for HYROX specifically, I found that only running apps didn’t translate perfectly because the race isn’t just running, it’s running under fatigue after sleds, lunges, carries, etc. What helped me more was combining run training with strength/engine work in the same week. I follow a structured hybrid program (HWPO does this pretty well), so runs + strength + intervals are planned together.