Can't find it on google play store. Can't go to their chinese website, always direct to USA site.
An alternative https://play.google.com/store/apps/details?id=net.pushl.agingheadphone&hl=en or simply search for 'Burn In Headphone' in the Google Play store.
It's like a simpler version of 1More's Assistant app, but it works well. I used it to burn in my KZ ATR and obtained good results.
If you still want 1More's Assistant app, you can download the APK file here http://en.miui.com/forum.php?mod=viewthread&tid=359223&extra=&highlight=1more&page=1
Before installing that APK file on your Android phone, make sure that you have 'install from unknown sources' turned on in security settings.
There's a latest version of the app than the one I linked to above, but you can simply do the update process via the app once it's installed.
IIRC, the 1More Assistant app is region-locked and is only available on the Play Store in certain countries. Don't know why.