This post convinced me to finally dump Duolingo since it's been getting worse and worse since they fired the translators.
I tried Busuu once before and I was frustrated because it looked like I had to start over. You don't. You can select the level you believe you are and do each checkpoint until you're where you believe you are. The lessons obviously don't match up and I found that Duo left way more gaps than I thought. But I can fulfill the lessons I want and still skip the ones I think I know by doing the checkpoints. They also have a lot more speaking by native speakers than Duo and I think it is more natural than Duo and in my (ten-year-old opinion) Rosetta Stone. I've only checked Spanish right now, so I can't say how well Japanese works, but to be honest, Duo was trash at it anyway.
As the post above states, Busuu does use AI for conversations and it's made it into Spanish. Right now, it's completely skippable and good thing because it comes with a warning that it will record you conversations for learning purposes. I'm hoping that feedback will keep Busuu from adopting this model.
My only real issue is that it's Spain Spanish and I was learning Latin American Spanish, so I really hope my brain is able to comprehend the difference (like I instinctually know the difference between American and British English).
i cannot keep quiet about this anymore.
if you're in the US or Canada and interested in learning a language using a free app please get a library card and download MANGO. it's very good and extremely free with a library card (there are many public libraries and universities using the service, so make an account and use the search feature here to find out if there's one near you).
mango currently has 72 available languages and dialects (that's right! different courses for french or canadian french! spanish or latam spanish!). it's set up basically like an audiobook with text. the idea is that the narrator explains the words while you read, and you repeat after them or say the translation out loud when prompted. there's a daily review where you go through flashcards. you can also use the flashcards at your leisure and create your own. at the end of each chapter there's a listening comprehension quiz and a reading comprehension quiz. i cannot emphasize how effective this all is. and it's free with a card.
if you're not in the US or Canada and/or looking for something more like duolingo (don't use duolingo btw tldr they fired translators and replaced them with "ai"), then try BUSUU! it only has 14 languages atm but the lessons are really descriptive and effective. it also has a feature where you can correct other people's open-ended speaking/typing exercises. you set your fluent languages, and exercises by people learning those languages will appear in your feed for you to correct. you can even add others as friends! and, much like duolingo, it has a streak and leaderboard system for you to strive for, minus the guilt-tripping owl.
busuu is free (you watch ads to unlock lessons and they're all skippable after like five seconds), although it also has paid premium/plus versions (i don't use the paid version—the language courses are available for free, and the ad system is Really unobtrusive).
so that's my wisdom for the day. mango and busuu. please check them out :)