This seems fine to me. There's a clear software component to the question, meaning that Android is (I can only assume) a relevant factor to the process. The fact that there is an app needed would lend more credence to this idea.
Where I would generally try to draw the line is: does something about Android as software have a meaningful impact? In cases where it's iffy then I think erring on the side of acceptance is certainly fine, but things that are likely to be considered off-topic are simply those where it is obvious that there are not any software considerations when using the accessory.
"How do I install a screen protector properly?" comes to mind as something that would fall into the latter (Android independent) category. Although instructions may vary between devices, it is not Android, the software, that causes that variance.