While I've only briefly skimmed it myself, I've heard a lot of good things about The Busy Coder's Guide to Android Development. Newer editions require a $20 "subscription", but older ones are available for free [1].
Raywenderlich.com is always my first pick.
This isn't necessarily conscious conspiracy on the part of the perpetrators. But it's a systemic attitude that ultimately has the same effect, and the incentives point in that direction. Remember, Google/Apple only make money on their respective app stores when you buy an app - free apps are worthless to them, as are apps you write yourself; free software apps that let you escape the ecosystem are worse than worthless!
Maybe they shifted focus to that in the past years.
I'm lazy and not very academic, and I feel like I always end up following a Medium or Hackernoon tutorial and using the official API docs for supplemental reference. I feel like this has been my experience for Flutter, React, ReactNative, Docker. I'm actually curious what folks' favorite 1st party docs are.
Also I really like React’s documentation. Previously, I had used random tutorials to get started but recently I went through their official docs to fill in gaps in my knowledge. Now I wish I had started with official docs in the first place.
[0]: https://en.wikipedia.org/wiki/The_C_Programming_Language
It trails React Native significantly.
This is perhaps one of the most commonly used widgets in Android: https://developer.android.com/reference/android/support/v7/w...
It doesn't say why it's deprecated and what it's replaced with. The link is even more confusing. And the document itself also doesn't say what a RecyclerView is or how to use it.
https://www.udacity.com/course/developing-android-apps-with-...
https://www.udacity.com/course/advanced-android-with-kotlin-...
That gives you a solid start to look into more details and do some codelabs on
https://codelabs.developers.google.com/?cat=Android
or watch a series about a certain topic on Youtube. I really like the Coding In Flow channel:
His 100 Days of Swift (and Swift UI) are also quite good to work through. He is widely known and respected in the iOS development community and works hard to keep it all up to date (all updates are included if you purchase his books).
I’ve loved them. Just chiming in to also suggest them.
I was interested in something similar, many years ago, and realized that the app I wanted to write didn't call upon any of the internal resources of the Android phone. So I was able to write it in Javascript / HTML, and it runs on any platform in a browser.
They're all outdated now, still in Java. It's open source, so I might actually get around to contributing to them.
Being able to ship to both platforms from the beginning creates a different kind of momentum.