BGSession is a lightweight local data storage, it can automatically synchronize their attributes value to NSUserDefaults.
##Install
source 'https://github.com/CocoaPods/Specs.git'
pod 'BGSession'
##Usage
Only need to inherit the BGSession, and then add the corresponding property.
Example:
DemoSession *session = [DemoSession sharedSession];
session.userName = @"Jack";
session.userId = @"1";
session.firstTimeUse = YES;
session.cityLng = 138.88383384;
session.cityLat = 63.8484848;
session.cityId = @1838;