Seedvault doesn't work half of the time.

They don't work well in my experience.

What I want is to get my home screen back exactly as I left it: I've not found anything able to pull it off on Android though.

Ideally it would be an exact flash image of the phone.

Adb backup exists, though I haven't tried it, and Google cloud backup does this. However, if you trust Google, you probably already trust the US.

Unfortunately, I don't know of any other app that does this on an unrooted phone.

Google cloud backup has never done this for me. It seems like it'll restore a whole lot of stuff, but details like getting my Nova Launcher screen back (version pinned to before it was sold - alternatives just aren't good enough yet) or a bunch of the little logins and details has never done it for me.

>Adb backup exists, though I haven't tried it,

It's very patchy, and many (most?) apps opt out, so it's functionally useless.

Nothing works on Android. Not even for basic app data. The biggest problem is keystore keys and e.g. bank authenticator apps tied to them.

AFAIK iPhone backups, if restored on the exact same device (i.e. a CPU with the correct decryption key embedded in it) will restore almost everything, including authenticator apps.

The only realistic option for Android is a separate "burner" device.

I agree they could be better; though I do get my home screen restored.

NANDroid dose the exact flash image, but with modern hardware rooted encryption it stopped being useful.