First of all, I can totally understand how questions specifically looking for cross-platform apps is a useful thing. However in a few minutes browsing here I have already seen a number of cases that seem unreasonable.
A great example would be this question:
Desktop OR Webapp? The body and comments go on to say that for desktop Windows OR Linux are fine. This is basically an overview question of every E-mail client in existence. This needs to be closed before the answers turn into [more of a] sludge-fest between every popular mail client.
An example of a cross-platform question that is at least somewhat meaningful would be:
That question has other problems but at least the need for the same client on two specific platforms is clear. A better example might be this one:
This doesn't require the same software on two platforms but it does require an inter operable solution where whatever is recommended for each platform can work together on the same data format.
My real question here is: What do we do when the criteria are tight enough to make o good question but multi-platform seems tacked on? Here is an edge case I would like to bring up and say we need to think carefully about how we handle this sort of thing.
In this case there seems to be something that meets all the specs, but there is an extra answer with a solution that only works for one of the requested platforms. If this is allowed we are going to flood our cross platform questions with answers that only support a subset of platforms. If we don't allow it, useful solutions for very specific problems that only fail the multi-platform requirement might be lost.
Should questions like this be edited to lighten up the cross platform from a requirement to a bonus, or should non-cross-platform solutions not be considered?