Searching for things online is pretty easy since the invention of search engines. However, there are situations, where you are searching for a product with specific details, which can be a very long process.
For example, just a couple of days ago I was searching for an open-source talking caller ID app for Android, and it was very hard for me to find one finally. (Just incase someone came here from a search engine, the app I have found is called Announcify.)
So, is there such a thing as a Stack Exchange site for asking other people if such a thing exists, or is it allowed to ask if such a thing exists on the product's related Stack Exchange site? That is for example, if you are asking if a programming tool exists, can you ask it on Stack Overflow? If no, why isn't this the case? It would be very helpful.