This website for vocabulary is simple but very nice, www.babadum.com from Poland. 21 languages available but still no Dutch :(

I’m learning Dutch with Babel. I like the App a lot, and it genuinely does it’s best to keep the learning process exciting.

Only downside are the costs.

Worddive is based in Finland and offers ten languages. I’m using it to learn Finnish.

Worth keeping an eye on Lingonaut. Still in early access at the moment, but looks like ot should be good when it releases properly

Have you tried or considered Language Transfer?

I loved Memrise for custom vocab decks, but they got rid of that feature in favour of focusing on their own language causes. I did their intro to Japanese about 10 years ago and I wouldn’t recommend it if you were seriously considering learning a language. I don’t know how it is now, but they didn’t really explain grammar, so you were left working it out based on the sentences it got you to memorise. If you actually want to learn a language through self-study, a textbook is the best way to go. And use Anki for vocab learning.

I liked Mondly, but never managed to stick to it.

I have just started using Duolingo. It’s very fun oriented, tries to be addictive. Don’t know yet how far it can take me.