Google announced on Google+ and Twitter that now you can add, edit or delete keywords within your AdWords campaigns directly in the Google AdWords mobile app on iOS or Android.

Here is a screen shot of the interface:

You can download the Google AdWords app on Android or iOS for free.

Here are instructions from their help docs:

From the Overview screen, scroll down and tap Keywords. Tap the plus button . Select a campaign, then an ad group for your new keyword. Tap + Add a keyword. Enter a word or phrase as your keyword, then choose the right keyword match type. Tap the checkmark . Tap Save, or to continue adding keywords to the same ad group, tap + Add a keyword.

Keywords, then tapping the plus button . You can also add keywords to a specific campaign or ad group by scrolling down, tapping, then tapping the

From the Overview screen, scroll down and tap Keywords. Tap the keyword you want to edit. From here, you can change the keyword or the match type.

If you change the text or match type for an existing keyword, the past performance data will be visible only in removed keywords.

From the Overview screen, scroll down and tap Keywords. Tap the the keyword you want to remove, then tap the trashcan . You’ll be asked to confirm before the keyword is removed.

From the Overview screen, scroll down and tap Keywords. Tap the plus button . Select a campaign, then an ad group for your new keyword. Tap Get keyword ideas. Enter a website or keyword related to your product or service. Select any keywords from the list that you want to adopt as your keywords. Tap Save, then tap Save again.

From the Overview screen, scroll down and tap Campaigns. Select a campaign. (Forecasting is only available for campaigns using manual CPC.) Scroll down and tap Keywords. Tap the plus button , then select an ad group. Tap + Add a keyword. Enter a word or phrase as your keyword, then choose the match type. Tap the checkmark . Tap See estimated impact. The results will tell you how the keywords you’re about to add might affect your campaign (impressions, clicks, and cost) next month.

Forum discussion at Google+ and Twitter.