If you have an Android phone or tablet, you may be habituated to downloading applications from Google Play application store. While downloading the apps, if the apps are large and/or the connection is spotty, the download will not proceed as expected and complete within desired time. In other words, your download may get stuck.
Such downloads are remembered by the phone/tablet and every time a connection is available, it will try and continue the download. As it happens, downloads are sequential in nature. Due to this, if you decide to download come new app, the new app will not get downloaded unless the presently stuck downloads are completed.
To overcome this problem, you can clear the pending downloads. To do so, do the following: Navigate to Settings >> Applications >> Manage Applications. Then select the ‘all’ tab, followed by ‘Download Manager’. For the Download Manager, click the ‘Clear Data’ button. Once complete, all pending downloads will be cleared and you will have a clear queue for downloads.