Update(2.0.0): Support for iPhone 6 / 6 Plus, iOS 8 and Background Sync

This is a major update for iPhone 6 / 6 Plus, iOS 8 and background sync.

Background Sync. Auto-Sync has been extended to run anytime. Get synced while you’re sleeping. (See more details at separate guide.)
Searched Folder. Searched words come into main sliding navigation.
Sliding UI for iPhone. Finally sliding UI is applied to iPhone. It takes full advantage of various screen size of iPhone 6 / 6 Plus.
From this version, free version has following limitations: Sync will be limited to max 10 feeds at a time.
From this version, we have ended support for iOS 6. To keep up development for RssBook, we decided to support only iOS 7 or later. (iOS 6 user still can use the earlier version(1.7.1) at App Store.)