EDIT: the owner has suspended the service, stating: "indefinitely [suspended]. Valid concerns were raised and I don't have the energy to rebuild it the right way."
Will do a write-up on this later.
Original post (shortened):
Threadstodon is a simple and clean toll to unroll #mastodon threads into an easy-to read format
Works exactly like you expect: give the thread URL, and you get an clean and easy-to-read formatted page of the thread back, that you can also easily share as well.