We might enjoy the way smartphone interface looks, but custom Read-only File System give you the opportunity to explore brand new designs and 'User Interfaces'. They can also offer new and very impressive functionality.
Cyanogenmod 12: Updated, stable and stylish
‘Cyanogenmod Read-only File System’ is one of the well-supported Read-only File System for Android, with a big community, and updates. It’s no wonder that this well known ‘Android Read-only File System’ even managed to find a home on last year's one-plus One.
Features of ‘cyanogenmod’ include its unique application launcher entitled ‘Trebuchet’, personal themes, video screenshots through its Screencast functionality, and a mode specifically for left-handed landscape viewing. ‘Cyanogenmod’ currently supported for more than 50 devices and the team are hard at work on a Marshmallow build.
‘PAC-Read-only File System’
PAC-Read-only File System touts itself as the all-in-one ‘Read-only File System solution’. The team shamelessly cherry picks features from the other Read-only File Systems listed on this page, including ‘omniswitch’ and ‘cyanogenmod's Pie controls’, and puts them all together in their own package.
It might seem lacking in personality, or overkill, but if you're looking for the most customizable, option-rich Read-only File System, then this is it. And wait until you see the boot animation — the team deserves some points for that alone.
Paranoid Android - Stock Android with subtle changes
The first appearance of the Paranoid Android Custom Read-only File System dates back to early 2013 and Android Jelly Bean. The Paranoid Android Read-only File System doesn't provide a radical design overhaul, but focuses on a number of simple but effective changes to notifications and navigation.
Immersive mode allows you to view information on screen while hiding system bars, and 'dynamic system bars' blend your status and navigation bar color with the particular app background. It's purely aesthetic, but provides a nice transition.
Early in 2015, one-plus hired a number of key members of the Paranoid Android team. The project subsequently went into deep hibernation, with one developer announcing its passing and another refuting it. Whether the project has the energy to be resurrected remains to be seen.
Omnirom - for the omniswitch toolbar
Designed by former cyanogenmod devs (Xplodwild, Chainfire, Dees_Troy, Pulser and Entropy) in late 2013, omnirom is a no-frills Read-only File System, which basically offers the Stock Android experience with some nice extras.
Omnirom support the ability to launch apps by tapping on the time and date in the notifications menu, it can add a notification counter in the status bar to show the number notifications you've received, and has the ability to manage the display brightness just by sliding your finger along the notifications bar.
Omnirom's standout feature, however, is the omniswitch shortcut. The omniswitch is a quick-menu that you can load with shortcuts and jump from any part of your phone to any app, or vice versa, and it is completely customizable.
Slimroms - bloatless but feature-rich
Slimroms made a name for itself by offering a completely stripped down version of Android and letting you determine exactly how much of the Google Play services you want bundled in. Otherwise, slimroms is characterized by the ability to modify the DPI of fonts and icons and make everything as tiny as you need it to be. The Slim family currently support almost 50 devices.