in development app

I am having a unique ed app developed by Russian/Ukrainians for people that want to learn English. The "make" is ready for revue and was sent to me with the following instructions"

"Logout from iTunes Store on device before launching application.
Start English From Pictures.
Log in on your iPod/iPad to iTunes Store with that Apple ID and password:
Apple ID: xxxxxx" plus the password.

"device" which device the iPad or the computer?
Start "English from Pictures" I presume on the iPad?
"Log in on your iPod/iPad to iTunes Store with that Apple ID and password:
THAT IS MY MAIN PROBLEM, ...HOW?
as you can tell I ain't the brightest, any help would be appreciated.

I'm pretty sure you want the App Store, not the iTunes Store on the iPad, though these instructions work for either one. On the computer these are combined into one store. On the iPad they are two different apps.

Anyway, to log into either store open the app and scroll all the way to the bottom of the page. You should see a box at the bottom left that either Says Apple ID: and shows your ID, or it will say Sign In (or something like). If you don't see it try a different view. The Category and Update pages won't show it, and maybe some other won't either. The Featured page always does.

If it says Sign In, tap it and enter your Apple ID and password when prompted. If it has the wrong Apple ID, then tap it to Sign Out, then go back to the previous sentence.

That should do it.