WhySoSlow is described as 'does a serious effort at analyzing your system to find out why it's running slow' and is an app in the OS & Utilities category. There are three alternatives to WhySoSlow for Windows and Online / Web-based. The best alternative is WhatIsHang, which is free. Other great apps like WhySoSlow are Crashlytics (Paid) and Doctor Dump (Free).
Doctor Dump is a free crash reporting and memory dump analyzing service. Its work is to collect software problem reports (crashes, failures, assert violations and so on) from your customers all over the world, to group them and to give you all necessary data to fix the problem.