One of the new features coming to the next version of Apple's mobile operating system, iOS 10, is the fact that developers will gain the ability to create animated emojis for the iMessage app, utilizing the Messages API.

As an update to this upcoming feature, Apple has released four emoji sticker packs into the App Store that can be downloaded and used by the beta testers of the upcoming mobile operating system.

The four sets come with simple names, specifically Classic Mac, Smileys, Hearts and Hands. The packs are not remarkable or grand in any way, but they show what developers would be capable of doing upon the release of iOS 10.

The Classic Mac set contains 8-bit icons that drew inspiration from the classic Apple computers, including a cursor, finger and magnifying glass emoji. The Smileys set, on the other hand, features a variety of faces by the familiar yellow-faced emoji, with each emotion conveyed by the emoji now much easier to understand due to the animations. The Hearts set contains only 10 emojis and shows different kinds of hearts with different animations. Lastly, the Hands set includes a variety of hand gestures made by a hand fitted with a white glove.

Upon the completion of installation, the animated emojis can be accessed through the redesigned Messages app of iOS 10, in the tab with the App Store icon.

The animated emojis, developed through the new Messages API, were first announced at Apple's Worldwide Developers Conference (WWDC) held in June.

The release of the API marks the first time that Apple is opening up its messaging platform to third-party developers, which will allow for add-ons such as stickers and the integration of iMessage for a variety of applications. For example, at the WWDC, Apple demonstrated iMessage apps that were able to order food for the user and complete payments through the Square service.

These four sticker packs are expected to join sets that were created by third-party developers once Apple releases the iOS 10 sometime this fall.

At the WWDC, Apple made a long list of important announcements. While there was no new hardware revealed, the company teased big changes coming to its variety of software and platforms.

The biggest announcements from the annual event, in addition to the iOS 10 update and new iMessage features, include a smarter Quick Type keyboard, voicemail transcription, a redesigned Apple Music, Apple News and Apple Maps, and the macOS Sierra update, which will see the integration of Siri to Mac computers.