Get itunes link for app before submitting
The easiest way to do this now is through iTunes Connect. Once you create an app there is a link to 'View in App Store'. Even if you haven't uploaded a binary yet you can click this link to get your App Store link.
The other answers work too but this generates your url for you. This is the URL it creates with my info removed (replace app-name and the numbers after /id with your own):
https://itunes.apple.com/us/app/app-name/id12345678?ls=1&mt=8
- The manual way:
Your should copy your "Apple ID" from iTunes connect and use this link:
http://itunes.apple.com/us/app/APPNAME/idXXXXXXXXX
Would open the US store ("APPNAME" is that app name and XXXXXXXXX is the "Apple ID". You can use more general method (Recommended):
http://itunes.apple.com/app/idXXXXXXXXX
and replace "XXXXXXXXX" with your "Apple ID" (from iTunes connect - after creating the app there).
Pay attention that those would open safari if you won't preprocess them, You could also use itms:// to open iTunes directly.