Availability of a name for an app in the AppStore

UPDATE 2015-01-05, per SarahR:

If you already have an app created, you can use its SKU for the app you want to check, and you'll get an error on submission that that SKU has already been used. If you don't remember the SKU you used for an existing app, you can go to the app details page, choose "MORE", then "about this app". If you don't already have an app created, it is plausible that you could create a dummy app with a name nobody would ever want to use, and then use its SKU to bounce the names you really want to test (though again, be wary of terms of service on that).

ORIGINAL:

The trick to checking the availability of a name while brainstorming is to not fill in the other required fields. Each field is checked individually. You do have to use iTunes Connect — "Manage Your Applications" -> "Add New App" (don't fill in a SKU Number or bundle id); if the name has been reserved, it will give you the following errors:

• You must select a Bundle ID.
• The App Name you entered has already been used.
• provide a SKU.

The second one is the winner, while the other two errors make sure you don't accidentally reserve the name before you're ready.

If you need to automate this process (which is probably against their terms of service), you can use any standard scraper. Mechanize is probably the most robust out of the box, but I think that's another question....

I use Google to check if an app name (or something similar to it) already exists.
Use this as your search query:

site:itunes.apple.com inurl:app clash of clans

(replace 'clash of clans' with the suggested app name of course)