Like better ways to learn a language than through an app or better apps?

For the first one, I'm still trying to figure that out myself. Principles that stand out to me are: believing that a language can be your own (as opposed to something you are simply memorizing/borrowing from foreigners) and learning things in context (as opposed to memorizing lists of words in isolation and never putting them into practice). These two together make a strong case for cultural immersion of actually living in a region whose language you want to live, but obviously that's not an option for a lot of people. There are the traditional methods like learning in classrooms and getting help from tutors, but these may not combine well with low money, low time, or both, which is probably why apps are popular.

For the second one, I don't really have any single one that I love. I've tried many different language apps and consistently run into some kind of issue, whether it's the cost being too high, or the design having elements I don't like, or the app creators making changes that (in my view) make it worse to use. That last one happened to me with HelloChinese. I do believe still that it has a lot of good learning material on it, but they changed the UI at some point to make it more like Duolingo's and literally made it harder for me to get through the lessons as a result because of the attention-grabbing design of the progress bar at the top. I'm probably more sensitive than some when it comes to that though, on account of distractability. I'd still recommend it to people who want to learn Chinese, so long as they can afford the monthly cost.

In general, the best bet is looking for an app that specializes in teaching a single language. Apps that boast of being able to teach you 10-30 languages or whatever, are probably doing a lot of cutting corners, copy/pasting, and might be okay if you're English learning Spanish or something, but are likely going to suck badly for languages with dramatic differences from your native one.

I've also experimented with apps that use AI for conversation practice. One example is TalkMe, which is okay. The catch is apps like that may have the reverse problem that the gamified language course apps have; if you have no familiarity with the language yet, they aren't giving you much of a foundation to learn on. Whereas an app like HelloChinese tries to give you more of a guided course foundation to work with.

For languages like Chinese or Japanese where you may want to be practicing writing Characters or writing Kanji, there are apps like Skritter (though I don't like the cost of it myself just for that one thing). More recently, I found something called ScriptPad, which is a pretty cheap one-time purchase for each language version of it you want to have and has practice for that kind of thing. So I got the Chinese version of it and have used it some to practice with writing/vocabulary.