Advanced Task Killer Android App allows you to stop running background processes or apps in memory. The Android operating system can run multiple apps in memory concurrently which currently is its own Gift and Curse. Cursed… as some processes and apps can bring an Android phone performance to a crawl. By default, you can’t easily close open applications or running background processes unless you go to:
Settings » Applications » Manage applications » (wait for list to load…) » (select app) » Force Stop ;-(
Not exactly convenient then…
The alternative is to download Advanced Task Killer from the market and use that instead. The name says “Advanced” task killer but it does everything TasKiller does; stops background processes and apps, specify an “Ignore List”, or kill all apps running with one button (at a higher cost without a home screen widget).
Link: Android Tapp