In this repository I store the source code (both the client and the server) for the iOS app "VK Exchange", previously available on App Store (2015 - 2017). The app had over 4.5 star-rating on the AppStore and has reached TOP-50 rankings in the Social category. The app was removed from the store in 2017 by me due to the lack of time to support the project.
"VK Exchange" was an app that let people exchange social value in VK social network. In order to start sharing the social value, the user had to:
- download the app from the App Store
- log in to the existing VK account (or create a new one!)
- grant the app access to the user's photos and feed
- use in-app currency to request other people to like your content
Authorization
The iOS app was built in Objective-C using powerful tools and 3-rd party libraries and SDKs. In order to log in to the VK social network I used VK SDK for iOS Cocoapod, which has a wide variaty of functions to synchronise the state with that of the social network account. Please look at VKAuthorizationViewController.m, where I handle authorization-specific actions (such as checking whether the SDK token has expired or not).
In case the required method was not available by VK SDK, I had to implement one by my own, primarily using the AFNetworking Cocoapod.
Analytics
When dealing with a user base of that size, it was important for me to ensure that proper analytics tools are embedded in the app. For that, I've successfully relied on Flurry-iOS-SDK pod.
Ads
As a way of monetization, I've used Vungle framework as a main ads provider. I've also used in-app purchases as a way to get in-app currency.
Other
As you can see from the Podfile file, I've also used many other utilities to further sharpen the user experience and to make the app more beautiful and reliable. The list of such frameworks is listed below:
MFSideMenufor implementing beautiful side menuSLCAlertView-ObjCfor handling alerts in a stylish waySVProgressHudto show progress during the loading of heavy items (e.g. photos)GBStoragefor easy and reliable persistent storage accross the user sessionMaterialControlsSpinKitNYXImagesKitColoursRMStore
The implementations of the server-side logic can be found in the server folder. The whole server-side was implemented using PHP in conjunction with PHP Data Objects to support seamless integration with SQLite 3 framework (see server/common.php:MyDB for more info). In order to prevent fraud, I've used hashing with a unique key (stored in iOS database) shared between the server and an application), see server/common.php:check_sha512 for more info. Note that the time of request was also hashed and stored on the server for 2 days, which ensured that no request could be repeated during the attack.
Overall, the implementation of the server could support 100k users in total and over 1k daily active users (up to 10 consecutive requests).