
iOS 9.3.3 seems to be an under-the-hood update. Meaning that the new firmware is filled with bug fixes and stability improvements only seen within the software's code. While there haven't been too many reports on what has been improved, some users have been reporting that apps have been "snappier".
iOS 9.3.3 beta 4 should be one of the final betas for this firmware. Usually after 4-5 betas, Apple ships out a build to the public for everyone to download. We expect the final software to be released at some point within the next week or two.