Apple unveils a new iPhone every year, most recently the latest iPhone 6s and iPhone 6s Plus. But many iPhone users are stuck on older versions: the 5s, 5c, 4s, or God forbid, something even older.
Every year, as your iPhone gets older and apps demand more processing power, your once lightning-fast model can slow down drastically.
However, there are a few things you can do to give your device an extra few months, or even year, of life.
Here are some of the options you have that can give a boost to your ageing handset. Most of them are only likely to provide a limited speed boost, however.
1 Clear your browsing history
Safari's browsing history doesn't only keep track of where you've been and when, it also stores cached pages and cookies from your browsing.
Caching pages allows you to load up certain pages more quickly, but racking up enough data can slow your iPhone down.
Clearing it every now and then can provide a small boost. Go to Settings -> Safari -> Clear History and Website Data
2 Turn off Background App Refresh
Many apps run in the background while not being used, checking data such as your location or refreshing the content on them so that, for example, a push notification is ready to read when you load it up.
The best apps are designed to limit the impact on battery life and performance by only refreshing at certain times, like when the iPhone is idle or plugged in. However, it is not always implemented correctly.
Disabling the ability of apps to refresh in the background means some apps may be slower to spring to life when loaded back up, but can improve performance.
Go to Settings -> General -> Background App Refresh to change this. You can turn off all background refreshes, or just ones that you don't need. Facebook and Skype are two that have been reported as being particularly active in the background.
3 Use Apple's apps
Apple's official apps - Mail, Camera, Maps, Safari and so on - have special permissions that often allows them to run more quickly and efficiently than third-party apps.
Of course, many people prefer alternatives like Google Maps, Chrome or Outlook, but if these are slowing you down, it may be worth it to switch.
4 Clear up some space
Clearing out files is an easy way to speed up your desktop computer, and getting rid of some of the apps and associated data taking up space on your phone can streamline it, possibly improving battery.
To see what apps are taking up the most space, go to Settings -> General -> Storage & iCloud Usage -> Manage Storage. It will show you what apps are taking up the most data. In some cases, as with apps like Twitter and Spotify, simply deleting and reinstalling them can free up a load of cached data.
Another way of clearing space is to delete all those old photos, once you've backed them up.
5 Reduce Motion
Those animations as you flick between apps look good, but they're another process your iPhone has to go through as you use it.
You can turn them off by going to Settings -> General -> Accessibility -> Reduce Motion.
6 Reset settings
A slightly more extreme step that will let you keep your apps and photos but will reset the iPhone settings such as your Touch ID, app permissions, display settings and so on, many people have reported improved performance with the reset, which is another way of spring cleaning your phone.
However, it will remove a lot of stored data such as Wi-Fi networks, alarms and Siri. It is only recommended if needed.
Go to Settings -> General -> Reset -> Reset All Settings to go through with it.
7 Full reset
Warning: This will delete everything on your phone and is only a last resort. It essentially lets you rebuild your phone from scratch (like when you first took it out of the box), although a couple of years of use means it still won't function as well as when you got it.
It is worth backing up your phone beforehand, although some of the speed benefits of a full reset are negated by putting everything back on.
To do this, go to Settings -> General -> Reset -> Erase All Content and Settings.
One thing not to do
It's a commonly-held misconception that closing apps in the background can save battery life or speed up your iPhone.
In fact, the opposite is true. Closing apps means that a lot of power is used opening them up again, while leaving them dormant in the background has little effect.