Why Android Phones Slow Down Over Time and How to Speed Them Up. I love the TV commercials that try to sell the unaware speed up tricks for their aging computer systems. For this post, I will assume you are not dumb enough to give the TV hucksters money to speed up your computer. This post by How-To-Geek gives some great tips for speeding up an aging Android system. The biggest cause of slowdown is the installation of a lot of programs that tie up system resources in the background. Learn your Android OS and you will be able to slim down the overload. Just as a clean install of Windows can speed up a system, you can reset and reinstall your Android apps in a couple of hours. If you haven't used an app in a month, don't reinstall it. Learn how to use the Settings feature. Eliminate bloatware, if you can. You'll be speeding up your phone or computer, and have more time to spend doing nothing.