Crewing someone
You don't need an account. Your runner sends you one link, and it has everything: when to leave, where to park, and a way to talk to them out there.
Before you drive
When your runner should come through, worked out from their training. When to leave, where to park, how far you walk in.
All night
Record a voice note, up to five minutes, and it reaches your runner on the trail. Family at home can open the same link and do the same.