The latest version of iOS is now available to download. The 9.2.1 update, while primarily a low-key maintenance update, is said to run smoother on older devices like the iPhone 4s and 5c.

While users are unlikely to notice any obvious changes to the operating system, under the hood there have been a series of security upgrades and minor bug fixes. It also solves a pesky Mobile Device Management problem that’s been affecting enterprise users.

What’s interesting is that after criticism and even a lawsuit about iOS 9’s sluggishness on the iPhone 4s, Apple seem to have responded by ensuring this latest iOS build runs a lot faster on those older iPhones. YouTube channel iAppleBytes has put together a basic comparison video below showing how 9.2.1 compares to 8.4.1, a version that almost a fifth of users have stuck with until now.

This smaller update will be followed in due course by iOS 9.3, which is already available in beta. When iOS 9.3 goes public it will bring a series of new features like Night Shift mode, new 3D Touch actions, improved CarPlay support and additions to the Notes app.

In the meantime, to manually update your iPhone or iPad to iOS 9.2.1 go to the Settings app and tap General followed by Software Update. Follow the instructions to download and install the upgrade.