- 我必须在我的Android 4.4设备上安装它吗？
I have some questions regarding Gapps:
GAPPS is not a custom ROM. It means "Google Applications" and usually includes Play Store, Gmail, Google Calender, and more. If you have some of these applications, then you already have some GAPPS.
Most users will only need to install GAPPS if they have installed a custom ROM that did not have GAPPS included.
"GApps" is an unofficial package distributed in several forms and places containing Google applications and frameworks, not a ROM. You don't have to install GAPPS, but many users may wish to do so in order to access Google Play store and some applications that depend on Google Play services. Smart phone functions such as calling, SMS messages, internet, Wi-Fi and Bluetooth work without GApps.
There's a replacement project MicroG in development and F-Droid is a comprehensive repository and "app store" for open source Android applications.