My answer to How can I increase my Android smartphone's speed?
Answer by Allen He:
Firstly, We should find out what is causing the problem. an app, multiple apps, the system itself?is a power and performance profiling application for mobile devices. It is designed to help you identify apps that hog your , consume excess data or drain your battery. Trepn can also produce app-specific or system-wide profiles and contains various methods for displaying accumulated data. You can save your profiled data for offline viewing and analysis and even have performance overlays on running apps. Once you’ve figured out your specific issue, you can move on to the solutions below.
Free up some space. Photos you’ve taken and apps you’ve installed can take their space on your phone. Until one day, all of these things take too much space on your phone. Your phone will be slower. It needs a little breathing room to run smoothly. You can check how much space you have left by heading to the Storage section of Settings. One of the easiest ways to free up space is to tap Applications and see which apps you can uninstall.
Tap the entry for an app you no longer need and then tap Uninstall. You can repeat this process as many times as necessary for any apps you feel you can live without.
There are other ways you can free up space. The files you have downloaded are probably still sitting in storage wasting space and can be removed. In Storage, tap Downloads, select the files you want to remove and then tap the Bin button.
Many of the apps you have installed use data caches in an attempt to speed up operations. This is effective up to a point, but if you are running short of space, it can actually be counter-productive. To free up this space, hit the Clear cached data option and then tap OK to confirm.
More files ripe for deletion can be found in the Miscellaneous files section. Tick the boxes next to any types of file you’d like to remove – backups, files received via Bluetooth, playlist files, and so on – and then tap the bin button. You can keep an eye on how much space you have freed up when you look at the Available space section.
You can stop use any apps that was pre-loaded on your phone. If you have rooted your Android, you can actually get rid of these apps, but if not, you can go to the app properties and disable it to prevent it from running and using up your phone’s resources.
Battery is one of the reason that makes phone slow. If your battery is low, many devices switch to battery-saving mode which runs the device in low-performance mode. If that’s the case, charge your phone as soon as possible. If you forget to turn off your phone or restart it for weeks or month, which would be another cause. So just restart your phone.