This is a very similar question to Is software identification on-topic?, but it's not identical.
I have recently been watching some screencasts, in which the caster has quite a few interested menu bar applications on OS X. I am curious as to what they are, but only have a small, simple icon to go by.
Would the posting of a picture of an icon and asking for that (or similar) software be on-topic on this site?
If your question is “what software has this icon?” then, going by the reasoning in the previous thread, no, it's off-topic. This isn't an icon identification site, this is a site where we recommend software to accomplish a task.
If the question is “what software was used in this video?”, then it might be on-topic, if you describe what the software was used for, what aspects of interface you liked, etc. A necessary condition to make the question on-topic is that if someone suggests software with similar functionality, it should still be a valid answer. For example, a functionally identical clone with different branding would be a valid answer. The icon could thus be an extra clue, but it cannot be a key requirement of the question.
