ColorOS 3.1 removed the traditional app drawer by default, organizing all apps on the home screen. Users who preferred an app drawer had to install third-party launchers.
The Oppo F3 is known as the "Selfie Expert" with a massive 4GB of RAM (for its time) and Dual-SIM capability. However, on the original Android 6.0, multitasking was clunky. Users had to choose between taking a selfie/video call and checking a message, or managing two different SIM cards (Work vs. Personal) required constant app switching. Oppo F3 Update Android Nougat 7.1.1