Is the accessibilityLabel needed if it's the same as label? If it is, then it's missing from the Move down button

+1 about the accessibility labels concern.
Current develop has labels with more information, that (I think) are also used on UI Testing.
https://github.com/wordpress-mobile/gutenberg-mobile/blob/40c1374072a37b5bdf4c8730af3b68f5a5fb0f09/src/block-management/inline-toolbar/index.js#L58-L74

And the prop to set the accessibility label is actually title.

Thanks for noticing, updating this 👍

This seems to be only used for its length, maybe getBlockCount is a better selector?
On the other hand, if we're not actually looking at the results of getBlockOrder, couldn't we use the length of normalizedClientIds instead to find the last one?

Actually, I just realized this is just what the web does. Do you think it'd make sense to share the select/dispatch logic and just fork the internal BlockMover component?

I'm not much in favor. Surely the components have similar names but they're not used the same way at the moment in web and native, I'd rather we keep them separated.
But in general, I'm all for reusing the web code whenever possible.

I think that flexbox allows for this without the extra spacer view, although I haven't managed to do it directly on the inspector slot without a wrapper view:

<View style={ styles.inspectorControls }>
	<InspectorControls.Slot />
</View>

.inspectorControls {
	flex-grow: 1;
	align-items: flex-end;
}

I think it makes sense with flexbox. It's not like we're floating our elements left and right, we're pushing it to the sides thanks to a spacer.
A good alternative would be to make 2 groups of icons, each using flex as well and justifying content to the left and right. I did experiment a bit with it but I saw some strange behavior with the toolbar disappearing sometimes. The current solution seems to be working fine for us...

On the first block, the move down button is read by VoiceOver as: "Move block down from row 1 to row 0".
It should say "... from row 1 to row 2".

The move up button is correct 👍

Thanks, for noticing, should be fixed now :)