ios7,8でアルバム名を指定して画像を保存する ref: http://qiita.com/roana0229/items/89f13d609116b33c8133

file0.txt

// 保存に成功した時
PhotoAlbumUtilResult.SUCCESS
// 保存orアルバム生成orアルバムに追加が失敗した時
PhotoAlbumUtilResult.ERROR
// アプリ内で写真へのアクセス認証を一度も行っていないか、認証が許可されなかった時
PhotoAlbumUtilResult.DENIED

file1.txt

let image = UIImage()
let name = "アルバム名"
PhotoAlbumUtil.saveImageInAlbum(image, albumName: name, completion: { (result) in
    switch result {
    case .SUCCESS:
        // 保存に成功した時
        break
    case .ERROR:
        // 保存orアルバム生成orアルバムに追加が失敗した時
        break
    case .DENIED:
        // アプリ内で写真へのアクセス認証を一度も行っていないか、認証が許可されなかった時
        break
    default:
        break
    }
})

PhotoAlbumUtil.swift

// Must import AssetsLibrary.framework(Required), Photos.framework(Optional) from Targets > General > Linked Frameworks and Libraries
import Photos
import AssetsLibrary

enum PhotoAlbumUtilResult {
    case SUCCESS, ERROR, DENIED
}

class PhotoAlbumUtil: NSObject {

    class func isAuthorized() -> Bool {
        if (UIDevice.currentDevice().systemVersion as NSString).floatValue < 8 {
            return ALAssetsLibrary.authorizationStatus() == ALAuthorizationStatus.Authorized || ALAssetsLibrary.authorizationStatus() == ALAuthorizationStatus.NotDetermined
        } else {
            return PHPhotoLibrary.authorizationStatus() == PHAuthorizationStatus.Authorized || PHPhotoLibrary.authorizationStatus() == PHAuthorizationStatus.NotDetermined
        }
    }

    class func saveImageInAlbum(image: UIImage, albumName: String, completion: ((result: PhotoAlbumUtilResult) -> ())?) {

        if albumName.isEmpty {
            completion?(result: .ERROR)
            return
        }

        if (UIDevice.currentDevice().systemVersion as NSString).floatValue < 8 {
            if  !isAuthorized() {
                completion?(result: .DENIED)
                return
            }
            var found = false
            let library = ALAssetsLibrary()
            library.enumerateGroupsWithTypes(ALAssetsGroupAlbum, usingBlock: { (group: ALAssetsGroup!, stop: UnsafeMutablePointer<ObjCBool>) in
                if group != nil {
                    if albumName == group.valueForProperty(ALAssetsGroupPropertyName) as! String {
                        found = true
                        library.writeImageToSavedPhotosAlbum(image.CGImage, orientation: ALAssetOrientation(rawValue: image.imageOrientation.rawValue)!, completionBlock: { (assetUrl: NSURL!, error: NSError!) in
                            library.assetForURL(assetUrl, resultBlock: { (asset: ALAsset!) in
                                group.addAsset(asset)
                                completion?(result: .SUCCESS)
                            }, failureBlock: { (error: NSError!) in
                                println(error.localizedDescription)
                                completion?(result: .ERROR)
                            })
                        })
                    }
                } else {
                    if !found {
                        library.writeImageToSavedPhotosAlbum(image.CGImage, orientation: ALAssetOrientation(rawValue: image.imageOrientation.rawValue)!, completionBlock: { (assetUrl: NSURL!, error: NSError!) in
                            library.addAssetsGroupAlbumWithName(albumName, resultBlock: { (group: ALAssetsGroup!) in
                                library.assetForURL(assetUrl, resultBlock: { (asset: ALAsset!) in
                                    group.addAsset(asset)
                                    completion?(result: .SUCCESS)
                                }, failureBlock: { (error: NSError!) in
                                    println(error.localizedDescription)
                                    completion?(result: .ERROR)
                                })
                            }, failureBlock:  { (error: NSError!) in
                                println(error.localizedDescription)
                                completion?(result: .ERROR)
                            })
                        })
                    }
                }
            }, failureBlock:  { (error: NSError!) in
                println(error.localizedDescription)
                completion?(result: .ERROR)
            })
        } else {
            if  !isAuthorized() {
                completion?(result: .DENIED)
                return
            }
            var assetAlbum: PHAssetCollection?
            let list = PHAssetCollection.fetchAssetCollectionsWithType(PHAssetCollectionType.Album, subtype: PHAssetCollectionSubtype.Any, options: nil)
            list.enumerateObjectsUsingBlock{ (album, index, isStop) in
                let assetCollection = album as! PHAssetCollection
                if albumName == assetCollection.localizedTitle {
                    assetAlbum = assetCollection
                    isStop.memory = true
                }
            }
            if let album = assetAlbum {
                PHPhotoLibrary.sharedPhotoLibrary().performChanges({
                    let result = PHAssetChangeRequest.creationRequestForAssetFromImage(image)
                    let assetPlaceholder = result.placeholderForCreatedAsset
                    let albumChangeRequset = PHAssetCollectionChangeRequest(forAssetCollection: album)
                    albumChangeRequset.addAssets([assetPlaceholder])
                }, completionHandler: { (isSuccess: Bool, error: NSError!) in
                    if isSuccess {
                        completion?(result: .SUCCESS)
                    } else{
                        println(error.localizedDescription)
                        completion?(result: .ERROR)
                    }

                })
            } else {
                PHPhotoLibrary.sharedPhotoLibrary().performChanges({
                    PHAssetCollectionChangeRequest.creationRequestForAssetCollectionWithTitle(albumName)
                }, completionHandler: { (isSuccess, error) in
                    self.saveImageInAlbum(image, albumName: albumName, completion: completion)
                })
            }
        }
    }

}