Jantastic is an interesting training tool that takes a community-focused approach to running fast. Think of it as an online training club. However, unlike ordinary clubs, there is far less time commitment.
There is no need to be anywhere at a certain time, run a particular distance, jump over flaming logs, climb electric fences or swim through ice cold pools of muddy water. Participants sign up as individuals or as part of a team, set their personal running goals and targets, share those and invite friends to join them.