Example implementation of FeatureCat's public board in an iOS UIKit app. It has all the code required in one single file for tutorial purposes - but it works.

featurecat.swift

import Foundation
import WebKit
import UIKit

// This is just an example ViewController that has been stripped of all code except the one relevant for FeatureCat.
class AnyViewController: UIViewController {
    
    // Excluded here: All the other code you need for your UI.
   
    // Return the WebView in whatever way suits you best (segues, etc.).
    private func featureCatWebKitController() -> WKWebKitViewController {
        // Create the FCUser with all of your properties. Only the user_id is required for FeatureCat and should be cached on device if it is only used for FeatureCat.
        let fcUser = FCUser(user_id: ...)
        
        // Grab the predefined request - or just define it here.
        var request = URLRequest.featureCatBaseRequest
        
        // Create a JSONEncoder for encoding the Codable FCUSer struct. Set the dateEncodingStrategy to ISO 8601 to make sure dates are formatted properly.
        let jsonEncoder = JSONEncoder()
        jsonEncoder.dateEncodingStrategy = .iso8601
                
        // Encode the fcUser struct you created earlier and attach ist to the request body on success.
        if let json = try? jsonEncoder.encode(fcUser) {
            request?.addValue("application/json", forHTTPHeaderField: "Content-Type")
            request?.httpBody = json
        }
        
        // Create w WebKitController (or hande the request in whatever way you prefer), attach the request and your good to go. 
        let wkWebKitController = WKWebKitViewController()
        wkWebKitController.request = request
                
        return wkWebKitController
        
    }
    
    
}


extension URLRequest {
    static var featureCatBaseRequest: URLRequest? {
        // Replace this URL with the one of your public board. Simply change the subdomain.
        guard let url = URL(string: "https://appity.featurecat.app/identify") else {return nil}
        var request = URLRequest(url: url)
        request.httpMethod = "POST"
        
        // Grab the token for your product from the product's settings in FeatureCat.
        let token = "yoursecrettokenasgeneratedbyfeaturecat"
        request.setValue( "Bearer \(token)", forHTTPHeaderField: "Authorization")

        return request
    }
}

// Creating these codable Structs is optional, but it does make the JSON creation a lot nicer. Instatiate these when creating the requests and fill them with your required data.
struct FCUser: Codable {
    let user_id: String
    let revenue: Double?
    let name: String?
    let email: String?
    let user_since: Date?
    let app_version: String?
    let user_properties: FCUserProperties?
}

struct FCUserProperties: Codable {
    let property1: String
    // Add whatever you need here
}