Software to train attacks-vision I'd like to train a sort of "chess vision". For a given position, I should find all the figures under attack, something very similar to schach-schlägerei: https://itunes.apple.com/de/app/id428235830

Unfortunately, this application is iOS-only. Suggestions for alternatives are welcome.
Chess Gym allows you to do that and much more (you can also try to find all the defended pieces in a given position). It's free and you can play without having to register.