Important update
Echo Thread is now TraceSpark
Same product, same team, same mission. Only the name changed.
If you followed a link or a bookmark to echo-thread.com, you are in the right place. TraceSpark, formerly Echo Thread, is the same product under a new name. The rename happened as the product grew past what the old name described, and nothing you were using went away.
TraceSpark is a reading and listening app for people past the beginner stage who already meet their target language in the wild. You capture a word from any app on your phone, and it comes back written into your next chapter, a story or podcast built at your level, in the dialect you named. It keeps returning until it sticks, scheduled by FSRS-6, the open-source memory model Anki ships.
Where to go next
Deciding whether this fits alongside what you already use is what the guides are for. They name competitors directly, including where those competitors are the better choice.