Two innovative suggestions
1.) Cross-lingual vocabulary practice: Many users learn more than one language. I am currently learning everything based on English. If I could learn vocabulary in between the different languages I could make more mental bridges as well as saving time reviewing them.
2.) Adding words: I have finished the Spanish tree and feel the need of adding vocabulary. Maybe this could be linked to the immersion section that one highlights new vocabulary and adds it to the vocabulary to be reviewed.
I am enthusiastic about Duolingo and am deeply grateful for what the team around Luis is doing to advance intercultural communication on such a grand scale. Thank you very much.
Thanks a lot for the suggestion. It seems to be a great addition to what Duolingo offers. I myself just find it difficult to keep up the discipline and rigor to go to various sites a day. I would prefer that Duolingo improves and becomes my only destination for intermediate language learning.