There are several third-party cloud storage apps offering services to iOS users for their iPhones and iPads besides its own native app, iCloud.

These cloud storage service keeps all the files and folders of the device synced for backup and sharing. User can also free some space on their devices by shifting the files to the cloud storage system.

There are a lot of great cloud storage applications available for iOS users in the Apple App Store. Following are the top 5 cloud storage applications for the Apple devices, which users can choose from.

Dropbox

Dropbox app is available for Apple iPhone, iPad, Mac, PC and other platforms. The user gets 2GB free storage space and the app also provides paid offers, starting from $9.99 a month,which goes up to the enterprise levels.

Dropbox is free-to-download app from the Apple iTunes Store and is compatible with iOS7 and up.

Download here.

Google Drive

Google Drive lets the user collaborate with all the products including Google Docs and spreadsheets from any browser. This app also supports several file types such as Photoshop, Illustrator and other video formats.

The user gets 15GB free storage, which can be upgraded to 100GB if the user pays $5 per month. Other additional upgrade plans are also available.

Google Drive is free-to-download app from the Apple iTunes Store and is compatible with iOS 6.0 and up.

Download here.

SkyDrive

SkyDrive is Microsoft's native cloud storage system which ties up with Microsoft Office Online and the full desktop version. The iOS users get 7GB to start for free, which can be further upgraded to additional storage space starting at $10/annum.

SkyDrive is also free for the iOS users and is compatible with iOS 6.0 and up.

Download here.

SugarSync

SugarSync syncs folders and backups just like any other app, but additionally lets the user upload or sync through emails, a feature that is not supported by any other app currently. Microsfot Outlook plugin is also offered which makes it easy to upload and save attachments.

SugarSync starts with an offering of 60GB storage space for $7.50 along with several higher plans, reports iMore.

The app is however free-to-download and is compatible with iOS 5.0 and up.

Download here.

Box.net

Box.net plays a dual role of a cloud storage service and of a collaboration tool for workgroups. This app offers typical features like other apps when used for personal work. For business users, Box.net offers a secure file transfer, marking up documents and notes. This app makes work projects fully accessible across groups of users who can view and edit notes.

A free personal account gives the user 5GB of storage space and 25GB for $10 per month. Business plan gives a bit more storage for $15 per month.

The app is free for iOS users and is compatible with iOS 5.0 and up.

Download here.