Or ask him/her what it is. If you want a quick answer, that's the way to get it.
And if you can't do that, or don't believe the answer, that's a bigger problem than the identity of the app.
(As ocnbrze has said, there are a vast number of apps that use icons like this, so searching is a waste of time. And we also get literally hundreds of these queries - yours was the second new one I spotted yesterday evening alone - and have to disappoint most of them).