&gt; the app had been developed on a mac, so it&#x27;s fairly easy to only test on webkit&#x2F;blink<p>It&#x27;s no harder to only test on Chrome in Linux and IE in Windows, I fail to see how that&#x27;s an excuse. The only excuses are IE testing when developing on OSX and Safari testing when developing on Windows, it&#x27;s trivial to install both Firefox and Chrome on any OS.