While for the most part performing regular maintenance on your computing devices is not needed, periodically you might want to check a few settings out and ensure your device and the programs on it are in optimal working order. For some platforms there are third-party tools you can use (though these are not necessarily required) for these purposes, but no such tools exist for iOS. However, there are only a few practices and settings you can tweak in iOS, that will give you the most out of your device.
Delete unused apps and data
As with any device, if you run out of data storage space, then you choke your device’s ability to work properly. In iOS, you should get warnings about there not being enough space to save data or perform some task, so in these cases your best bet is to delete unused apps, photos, movies, and other data from your system.
This same detail goes with any data you use in your apps. If you have a massive set of documents specific to one app, be it movie files, photos, or otherwise, then these could collectively eat away at the storage on your device, so go through your apps’ libraries and remove files you don’t need anymore.
Keep your device updated
Go to Settings > General > Software Update and apply any security patches available for iOS. Then go to the App Store and tap “Updates” and apply any app updates that are available. Generally, ensuring you have the latest software running on your device will have you at the forefront of any bugs or problems that might be in the software you use.
When it comes to full upgrades of iOS, such as going from iOS 8 to the upcoming iOS 9, while in the past newer versions of OS software have put more demand on your device, this is not necessarily the case with newer versions of iOS. Apple’s new Metal API in iOS promises to give developers far better access to the device’s computational power and optimize the responsiveness of their apps, which has the potential to breathe new life into older systems. However, this will take time to implement, so your best bet in this transition is to keep your device and software updated.
Disable unused background services
Apps in iOS can refresh in the background and have access to location data, which should individually have relatively minimal impact on your system, but collectively may cause a performance hit. Therefore, go through your settings and disable these for all except the apps you specifically need them for. These settings can be found in Settings > General > Background App Refresh, and in Settings > Privacy > Location Services.
One approach here is to preferentially disable these settings if you are in doubt about whether your need them for a program, and then let any warnings from the programs you use spur your need to re-enable these settings.
Finally, as with all devices, be sure you maintain your backups. Apple supports iCloud-based backups where your settings and documents are saved, and can be restored along with your purchased apps and iTunes contents on the event you need to reinstall iOS. This can be set up by going to Settings > iCloud and enabling the Backup service.
Alternatively, you can back up your iOS device using your Mac. Attach your device to your Mac, and then open iTunes, were you can select the option to either have your device backup to iCloud or to your Mac. You can also manually backup your device regardless of these settings. With your Mac set as the backup device, you can have it back up automatically by making it a habit to plug your phone into your Mac when you need to charge it, or set your iPhone to automatically sync via Wi-Fi and the backups should occur whenever both your Mac and iPhone are on.