At the moment I'm supplementing duolingo by nattering away to my father in French and asking the half-French guy at work how to say various things, but if the app is teaching me things that are plain wrong, I'll have to either find another app or start taking real life classes, which is why it would be useful to know what else is broken.
My chronological progression of picking up French via apps/courses (lots of trial-and-error):
1. Duolingo
2. Michel Thomas audio course - this has its critics but it gave me a much more solid, if limited, foundation on grammar.
3. Lingvist - I was lucky to find this early. Added around 2000 words to my vocabulary (yes they claimed ~5000 - that was inaccurate; conjugations and plurals are counted separately). Today you need to pay $23 / month to get the same number of words.
4. Clozemaster - it offers a lot more words, so I got a paid subscription. Got disappointed really fast though because its automated method to offer mass sentences really shows its flaws quickly: there are many errors and nonsensical cloze placement. I got tired of flagging.
5. Assimil - seems good, but without any gamification or anything I can play on my phone while waiting, commuting, etc., this soon dropped off the radar.
6. Speechling - this one should not have the problem of Clozemaster or Duolingo, because they have a human teacher correcting your speech. I imagine their sentences are more carefully curated as well. I started the trial, but dropped after a while because I found I just couldn't allocate the time to sit in a quiet place and record myself for an extended amount of time. Yes, it's a genuine "it's not you, it's me" thing. I really like their recent features and will probably try this again during a less hectic life period. Hongyu (the CEO) is super responsive too, which is great.
7. Glossika - this is what I'm currently on. It's not perfect; their main thing is you hear someone saying X in English and a moment later the equivalent in French. They offer mass repetitions as well, with the same class of problems: occasional inaccurate translations. The reason I picked this one instead of Speechling is not quality: it allows me to listen to mass sentences while doing mindless boring stuff that I have to do anyway (e.g.: doing the dishes, walking to/from the subway station, etc.). This allows me to get French exposure every day, even if not perfect, which ends up meaning more exposure than what Speechling can give me.
8. I'm a subscriber of one more app, I can't believe I forgot to add this one the first time: Kwiziq. They have a very specific target: teach you grammar from A0 (i.e.: the level below A1) to C1. My main problem is that they don't have an "aging" feature. Something I learned fully in A1 9 months ago will be forever marked as "mastered", despite my having forgotten it completely. Nevertheless I continue to be a happy subscriber. It's fun to finish a quick grammar quiz here and there as you're waiting for food, queueing for stuff, etc.
CEO of Speechling here. We'll work on (7). It's trivial to implement. We want the functionality of (7) to be better and free.
Hongyu
Everything else e.g.: Assimil is a workflow interruption, a new habit I have to assimilate, so it becomes a lot harder to do consistently over a long period of time.
After this thread, I plan to move that step up as a check on DuoLingo.
Since then by my estimate I know roughly about 4000 more French words, and reading lemonde.fr is still a struggle. Doing much better with Tintin though.