发现了一个获取指定 APP 详细信息的 App Store 接口

1. 比如微信的 App Store 地址是 https://itunes.apple.com/cn/app/wei/id414478124
2. 提取上面地址的 id 参数，即上面链接的末尾部分：414478124
3. 请求这个地址： https://itunes.apple.com/lookup?id=414478124，就会返回包含 APP 所有信息的 json 格式的文本文件，示例如下：

{
 "resultCount":1,
 "results": [
{"isGameCenterEnabled":false, 
"ipadScreenshotUrls":["http://is2.mzstatic.com/image/thumb/Purple117/v4/a1/69/ac/a169ac6e-312b-309c-c11a-89ba48a01d39/source/576x768bb.jpg", "http://is5.mzstatic.com/image/thumb/Purple117/v4/b7/53/6e/b7536e0b-0a6d-ec79-c146-0e29db308817/source/576x768bb.jpg", "http://is5.mzstatic.com/image/thumb/Purple127/v4/b7/78/80/b77880be-8629-88ab-8e31-1debff900e83/source/576x768bb.jpg", "http://is1.mzstatic.com/image/thumb/Purple127/v4/66/28/fe/6628fe0d-66f1-e476-d9a2-7828cb32cdcc/source/576x768bb.jpg"], "appletvScreenshotUrls":[], "artworkUrl60":"http://is2.mzstatic.com/image/thumb/Purple128/v4/0f/60/a4/0f60a464-0d94-40cc-f781-c813b090a707/source/60x60bb.jpg", "artworkUrl512":"http://is2.mzstatic.com/image/thumb/Purple128/v4/0f/60/a4/0f60a464-0d94-40cc-f781-c813b090a707/source/512x512bb.jpg", "artworkUrl100":"http://is2.mzstatic.com/image/thumb/Purple128/v4/0f/60/a4/0f60a464-0d94-40cc-f781-c813b090a707/source/100x100bb.jpg", "artistViewUrl":"https://itunes.apple.com/us/developer/wechat/id614694882?uo=4", "kind":"software", "features":["iosUniversal"], 
"supportedDevices":["iPad2Wifi-iPad2Wifi", "iPad23G-iPad23G", "iPhone4S-iPhone4S", "iPadThirdGen-iPadThirdGen", "iPadThirdGen4G-iPadThirdGen4G", "iPhone5-iPhone5", "iPodTouchFifthGen-iPodTouchFifthGen", "iPadFourthGen-iPadFourthGen", "iPadFourthGen4G-iPadFourthGen4G", "iPadMini-iPadMini", "iPadMini4G-iPadMini4G", "iPhone5c-iPhone5c", "iPhone5s-iPhone5s", "iPadAir-iPadAir", "iPadAirCellular-iPadAirCellular", "iPadMiniRetina-iPadMiniRetina", "iPadMiniRetinaCellular-iPadMiniRetinaCellular", "iPhone6-iPhone6", "iPhone6Plus-iPhone6Plus", "iPadAir2-iPadAir2", "iPadAir2Cellular-iPadAir2Cellular", "iPadMini3-iPadMini3", "iPadMini3Cellular-iPadMini3Cellular", "iPodTouchSixthGen-iPodTouchSixthGen", "iPhone6s-iPhone6s", "iPhone6sPlus-iPhone6sPlus", "iPadMini4-iPadMini4", "iPadMini4Cellular-iPadMini4Cellular", "iPadPro-iPadPro", "iPadProCellular-iPadProCellular", "iPadPro97-iPadPro97", "iPadPro97Cellular-iPadPro97Cellular", "iPhoneSE-iPhoneSE", "iPhone7-iPhone7", "iPhone7Plus-iPhone7Plus", "iPad611-iPad611", "iPad612-iPad612", "iPad71-iPad71", "iPad72-iPad72", "iPad73-iPad73", "iPad74-iPad74", "iPhone8-iPhone8", "iPhone8Plus-iPhone8Plus", "iPhoneX-iPhoneX"], 
"screenshotUrls":["http://is5.mzstatic.com/image/thumb/Purple127/v4/23/c0/dd/23c0dde6-f43b-d13b-ff12-f3dd0fc2911d/source/392x696bb.jpg", "http://is1.mzstatic.com/image/thumb/Purple122/v4/33/fa/38/33fa3803-cbbe-19e2-3225-efda30868629/source/392x696bb.jpg", "http://is4.mzstatic.com/image/thumb/Purple127/v4/84/94/a5/8494a587-b41d-843a-5f62-245124cf12f7/source/392x696bb.jpg", "http://is3.mzstatic.com/image/thumb/Purple117/v4/4b/35/22/4b352282-6178-8b3a-94f4-4a20df147ea1/source/392x696bb.jpg", "http://is4.mzstatic.com/image/thumb/Purple127/v4/43/8c/0a/438c0a11-f8b4-2458-6953-1003b293c7f1/source/392x696bb.jpg"], "advisories":["Infrequent/Mild Sexual Content and Nudity"], "averageUserRatingForCurrentVersion":4.0, "trackViewUrl":"https://itunes.apple.com/us/app/wechat/id414478124?mt=8&uo=4", "contentAdvisoryRating":"12+", "trackCensoredName":"WeChat", "languageCodesISO2A":["AR", "ZH", "EN", "FR", "DE", "HE", "HI", "ID", "IT", "JA", "KO", "MS", "PL", "PT", "RU", "ZH", "ES", "TH", "ZH", "TR", "VI"], "fileSizeBytes":"228399104", "sellerUrl":"http://www.wechat.com", "userRatingCountForCurrentVersion":161, "trackContentRating":"12+", "primaryGenreId":6005, "sellerName":"Tencent Technology (Shenzhen) Company Limited", "genreIds":["6005", "6007"], "currentVersionReleaseDate":"2017-11-29T07:54:35Z", 
"releaseNotes":"In this update \n- Compatibility with iPhone X \n- Filter your chat history for payment transactions\n- Set a reminder to alert you later of a chat message\n\nLatest updates \n- Notes in Favorites can be formatted with bulleted and numbered lists, and notes can be set to Sticky on Top of the chat screen\n- Generate your own tipping code and present to others to receive tips from other users (China-only)\n- Improved chat history search experience\n- A whole new design for iPad including an dual column layout", "currency":"USD", "wrapperType":"software", "version":"6.5.23", "artistId":614694882, "artistName":"WeChat", "genres":["Social Networking", "Productivity"], "price":0.00, 
"description":"WeChat is a messaging and calling app that allows you to easily connect with family & friends across countries. It's the all-in-one communications app for text (SMS/MMS), voice and video calls, Moments, photo sharing, and games.\n\nWHY USE WECHAT:\n • MULTIMEDIA MESSAGING: Send video, image, text, and voice messages.\n • GROUP CHAT & CALLS: Create group chats with up to 500 people and group video calls up to 9 people. \n • FREE VOICE & VIDEO CALLS: High-quality free calls to anywhere in the world.\n • WECHAT OUT CALLS: Make calls to landlines and mobile around the globe at low rates (in certain regions only).\n • STICKER GALLERY: Hundreds of free, fun, animated stickers to express your feelings from some of your favorite cartoons and movies.\n • MOMENTS: Share your best moments on your personal photo stream.\n • BETTER PRIVACY: WeChat gives you the highest level of control over your privacy. It's the only messaging app to be certified by TRUSTe.\n • MEET NEW FRIENDS: Use “ Friend Radar ”, “ People Nearby ” and “ Shake ” to meet others. \n • REALTIME LOCATION: Instead of having to tell others where you are, just use real-time location sharing.\n • LANGUAGE SUPPORT: Localized in 20 different languages and can translate messages to any language.\n • WeRun-WeChat: Access HealthKit data and challenge friends to beat their scores via the \"WeRun-WeChat\" Official Account.\n • AND MORE: Desktop app, custom wallpapers, custom notifications, and Official Accounts.", "trackId":414478124, "trackName":"WeChat", "bundleId":"com.tencent.xin", "isVppDeviceBasedLicensingEnabled":true, "primaryGenreName":"Social Networking", "releaseDate":"2011-01-21T01:32:15Z", "formattedPrice":"Free", "minimumOsVersion":"8.0", "averageUserRating":4.5, "userRatingCount":39974}]
}