Just another angle at defining the fuzzy boundaries of things here. Say I'm looking for a Books app with barcode scanning and GoodReads integration, is asking whether one exists and what it is on topic or too subjective?
The pertinent question, of course, is how much the additional criteria narrow it down.
For example, if you ask for a browser app with bookmarks, that's pretty lame - they all have that. Your example of a books app with barcode scanning and GoodReads integration is much better because it narrows it down to probably less than 5 or so apps.
Of course, the voting is still pretty meaningless, but at least it's not an open invitation for everybody to post their favourite app.
So for the most part, yes, I would say that the question format is valid, although individual questions would still have to be evaluated individually with respect to how meaningful the constraints are.
I agree with Aaronaught but I'd like to add a criteria in determining the quality of such questions:
Can the question be answered by a simple search of the Market?
If it can, then the asker shouldn't ask it they should use that energy to search the market. An example of this could be...
Is there an app that lets me use my LED flash as a flashlight?
I need an app that will turn my phone into a flashlight.
This should never be asked. Simple searching "LED flashlight" brings up numerous apps that do exactly that.
Here's an example of a what I consider an acceptable app recommendation question:
GPS app that will track my movements and record route, distance, time & elevation?
Is there an app that will track and record my bike tours and accurately record the route, distance & elevation, and the time I was at each point of the route? I also need to be able to view these recorded tours on my computer afterwards so I need a PC component or a way to export the data into a format that's compatible with some 3rd party GPS tour software like MyTourBook. I've tried MyTracks and GPS Tracker however neither of them seem to accurately measure my elevation or the time that I was at certain points along my route.
You could search for GPS apps in the market but it would be difficult to parse out which apps effectively meet the complex set of criteria above. While this is a fairly specific request, it's not obscure. I can see a lot of applications for an app that meets said criteria so I think it's likely that others have searched for this and will in the future.
My 2 cents: This is a good question that needs to be answered in meta but I think theres too much paranoia over "Subjectivity." Whether an app that provides a particular function or not is not subjective at all. Either the app does or it doesn't. People are conflating "questions that have more than one answer" with "subjective question."
To be on the safe side, such questions can be posted here instead:
At the time this question was asked, well-defined requests for recommendations were acceptable here. That is no longer the case.
Sometimes the Asker will argue that they're not asking for a recommendation, but rather just if such an app exists. It amounts to the same thing. "Help me find an app that meets my specific requirements" is a request for a personalized search service. And, even if we were willing to do that, the universe of apps changes all of the time. The purpose of Stack Exchange is to provide answers to questions that will help many more people than just the Asker.
So questions of this type should be closed.
I just saw a question a few minutes ago that was asking about if there was anything he could do to temporarily be unblocked by a person on WhatsApp, but it was closed by an admin because it was too subjective.. I think that if someone was looking for an app reveiw,, he should read the app description first, then the reviews instead of bothering us with their laziness.