It turns out, one way to reduce the size of a Flutter app, is by splitting it into builds for each specific device architecture you want. So if you type:
flutter clean; flutter build apk --split-per-abi
It'll give an output like:
✓ Built build/app/outputs/flutter-apk/app-armeabi-v7a-release.apk (6.9MB)
✓ Built build/app/outputs/flutter-apk/app-arm64-v8a-release.apk (7.4MB)
✓ Built build/app/outputs/flutter-apk/app-x86_64-release.apk (7.6MB)
Now I needed to know which one I could use on my phone, and realized that in all these years, I didn't bother finding out what architecture my phone was running.
So I activated Developer Options and USB Debugging on my phone and did the following:
sudo apt update; sudo apt install adb
Now ADB (Android Debug Bridge) should be installed. To see which devices you can connect to via ADB, type:
adb devices
You'll be asked on your phone for permission to do USB debugging. Grant it.
Now either type:
adb shell uname -m
Or, just:
adb shell
And then type:
uname -m
And now I know the phone is armv7l, which is an ARM 32 bit architecture.
So now I know I could have also tried:
flutter build apk --target-platform android-arm --analyze-size
There are many other ADB commands:
To copy files:
adb pull /path/to/phone/file /path/to/desktop/folder
Mount the phone onto the Linux filesystem:
sudo apt install adbfs
mkdir ~/android
adbfs ~/android
Now you can access the files via your desktop computer at ~/android
To get elevated permissions with ADB:
adb kill-server
sudo adb start-server
adb devices
For more commands, simply type:
man adb
