fire tv stick 4k 上面，试了几个app，Google Photos和Photo Gallery and Screensaver都没法登录Google帐号，后来发现 pFolio 可用。

用pFolio替换自带屏保，参考http://www.aftvnews.com/how-to-change-the-default-screensaver-on-the-fire-tv-or-fire-tv-stick/

» adb connect 192.168.2.xxx
» adb shell
settings put secure screensaver_components com.snapwood.photos2/com.snapwood.picfolio.DreamService

settings get secure screensaver_components

如果需要改回去
settings put secure screensaver_components com.amazon.ftv.screensaver/.app.services.ScreensaverService

修改启动屏保时间为1分钟（默认值300000为5分钟）
» adb shell settings put system screen_off_timeout 60000