I’m not trying to undermine the idea that Star Trek was progressive for its time, far from it, but since no one else has pointed this out, I thought I’d say it. Star Trek was NOT the first interracial kiss on television. In fact, the actors’ lips never touched in the shot.
Well, sort of. I’ve been reading William Shatner’s autobiography, and they had to fight really hard to include an interracial kiss. The network was going to forbid it, telling Rodenberry that televisions across the South would rather black out their televisions for an hour than allow something so highly offensive. When he insisted upon it, they kept making concessions Rodenberry wouldn’t agree to, like instead having Uhura kiss Spock, since it there would be a little more disconnect between reality. Eventually, Rodenberry offered to film the kiss both ways—one way with their lips actually touching, the other with Uhura’s back to the camera as they embraced, giving the illusion that they kissed without their lips ever touching. The actors were really upset about it, because It was originally going to be a passionate kiss, but the only way they allowed it to be filmed on television was if the actors displayed clear discomfort—which could be used to reinforce the idea that interracial relationships were bad.
Soo…yeah! That’s your Star Trek history lesson for the day! (I’ve never watched the original episode, I’ve only watched TNG and Discovery for myself, so this is all secondary info, but if you watch the episode, you can see for yourself.)
I started looking for alternatives when they added the weird character voices and I started noticing inaccurate pronunciation of kanji in my Japanese course. A lot of people on the message boards recommended Memrise, and it's been great! The official courses contain actual video and audio of native speakers, so I knew for a fact the pronunciation would be correct---even better than the old Duo voices!
There's also user-generated content, too, some of which might not be accurate, but most of the user courses I've found are pretty good. You can even make your own set and publish it.
(I haven't visited the site in a few months, so I can't guarantee it'll be exactly as I found it, but I doubt it has changed much)
And depending on what languages you're studying, you might be able to find some good ones dedicated to your language if you do some digging. For Spanish, I used SpanishDict, and for Japanese, I used Kanshudo (both are freemium, with more restrictions than Memrise)