Most if not all android devices have a built in task manager which shows you all the background apps (running apps) and lets you selectively remove them from memory.
Keeping them running will pull them up faster when you need them, but beyond a point, too many apps will slow the device down. the app manager is usually pulled up with a long press on the home or options button.
If you need to install a third-party app to do the same thing, you can get advanced task manager (by infolife) or android app manager (by smartwho).
The advantage that either of these apps can offer is a home screen widget which allows you to close running apps with just one tap.
Guard against malware & bad apps
If you download a lot of apps from unknown sources (places other than google's play store), chances are that your phone is already infected with malware.
Trend micro reports that there are over 500 sources that host malicious apps. While most malware will send texts to premium numbers without your knowledge, some could also be mining data (and consequently slowing down your device).
If you must get apps from unknown sources, you should get an anti-virus app. some of the best free options include avast, avg, lookout, norton, eset & zoner.
Note that you shouldn't install more than one of these at one time and having one isn't a guarantee against bad apps — but it helps.
Manage RAM for smooth multitasking
One of the biggest reasons why your device runs out of steam is limited available RAM. This is more true of devices with 512MB and to a certain extent, 1GB of total RAM.
Depending on the number of applications you have installed (and how many of them are running in the background), the amount of free RAM your device has may not be enough to smoothly switch between apps.
To solve this problem, get a free app called Clean Master by KS Mobile. Not only does it have a task killer (to free up RAM), but it can also delete history (web browser data & history), clean the cache, properly uninstall apps and remove residual files (remnants of previously deleted apps) to free up space on the device memory.
Get your settings straight
Take a look at your device's settings page. are you signed in to any accounts that you are not using? remove them. you can also check for sync intervals (how often these accounts check for updates).
Are additional functions like bluetooth, nfc and wifi on when you don't need them? some of these might keep hunting for a connection and slow down other services. if you are using a third-party launcher, set it as the default.
If you use more than one launcher at a time, resources are usually shared between them, making everything slower. it also helps if you remove any widgets that you aren't using (because they keep updating in the background) and remove any extra homescreen pages.
Get a fresh start
Sometimes, whatever you do may not be enough. If your phone or tablet still keeps freezing or drags its feet with even the simplest of tasks, it may be time for a factory reset. A factory reset restores your device to original settings — like the way it was when you first got it.
Luckily, every Android device has a factory reset option built in.
Initialising the factory reset is a simple, one-step process — just head to settings and 'privacy' or 'backup & reset'. Keep in mind that doing a factory reset erases everything on the device: all installed apps, contacts, calendar entries, photos, texts, videos & any accounts that you're signed in to will be removed. So before you reset, use an app called inDefend to backup your contacts & messages, use App Backup & Restore (by Infolife) to backup apps, SMS Backup & Restore for SMS & Dropbox to save your photos & videos to the cloud.
Periodically clean out messages and gallery-
If you've owned your phone for a while, chances are you have thousands of texts, photos & videos stored. You can take a backup of all essential data and clean out stuff — starting from the oldest first. Since these apps won't have to cache as much data, they'll load much faster.
How much free phone memory do you have-
Even if you have 16GB storage, some of that is taken up by the operating system and essential apps. You should keep at least 2GB of that free. Move all non-essential data and apps to the external memory card using the file manager and a free app called App2SD.
Does the stock launcher slow you down -
Phone makers have a tendency to use heavy interfaces with animations & features that you may never use. Download Nova Launcher from the app store to give your device an instant speed boost. It's also way more customisable than the stock interface that you get.
Live wallpapers use up processor bandwidth -
Using a live (animated) wallpaper on your device uses up a fair bit of processing power — power that could easily be put to use by making apps load up faster and making the interface smoother. While this is more true of budget devices, switch off your live wallpaper and you'll also see better battery life.
