{
    // image data
    imageList: imageList,
    // custom album name
    albumName: albumName,
    // cache dir name
    cacheDirName: cacheDirName
}

var imageList = [
    {
        fileFullName: 'xxx.png',
        cacheFileName:'ab112ssq.png',
        imageUrl: 'http://xxx.png'
    }
];
var cacheDirName = 'cacheDir';
var albumName = 'Custom Album';

if (window.plugins && window.plugins.ImageSave) {
    window.plugins.ImageSave.saveToAlbum(JSON.stringify({
        imageList: imageList,
        albumName: albumName,
        cacheDirName: cacheDirName
        }), function (data) {
            // Success
        }, function (error) {
            // Error
        });
} else {
    console.log("Please intall the plugin.");
}

function (data) {
    // data : {code: 100, message: 'xxxx'}
}

function (error) {
    // error : {code: 120, message: 'xxxx'}
}

- (void)openSetting {
    NSURL *url = [NSURL URLWithString:UIApplicationOpenSettingsURLString];
    if ([[UIApplication sharedApplication] canOpenURL:url]) {
        [[UIApplication sharedApplication] openURL:url];
    }
}

/application dir/Library/files/cacheDir/

/External Path/cacheDir/

File Transfer Error: Invalid server URL 'xxxxxx'

Before 'NSURL* sourceURL = [NSURL URLWithString:source];'
Add below line
(ios 7 later)
source = [source stringByAddingPercentEncodingWithAllowedCharacters:[NSCharacterSet URLQueryAllowedCharacterSet]];