Some apps are not worthy to be downloaded, after downloading such apps, you begin to wonder how that app made it to the blackberry world. The next thing, you delete the app but its still in the my world section of the blackberry app world.

You can completely remove all your un-installed app from blackberry app world by re-setting the app world.

To reset your blackberry app world, simply open blackberry world, click on the my world section, press and hold the alt button then type rst. Your app world will automatically reset. in the process, flushing away all un-installed apps.
Source:http://www.weselion.com/how-to-delete-un-installed-apps-in