The characters in the string "do the wave"!

AnimatedWaveText.swift

import SwiftUI

struct FloatEffect: GeometryEffect {
    var animatableData: CGFloat
    
    func effectValue(size: CGSize) -> ProjectionTransform {
        ProjectionTransform(CGAffineTransform(translationX: 0, y: sin(animatableData) * 12))
    }
}

struct AnimatedWaveText: View {
    
    @State var chars: [String]
    @State var sinOffset: CGFloat = 0.0
    
    var body: some View {
        HStack {
            ForEach(chars.indices, id: \.self) { index in
                Text(self.chars[index])
                    .foregroundColor(Color(hue: Double(index) / Double(self.chars.count), saturation: 1.0, brightness: 1.0))
                    .modifier(FloatEffect(animatableData: CGFloat(index) + self.sinOffset))
            }
        }
        .onAppear() {
            withAnimation(Animation.linear(duration: 4.0).repeatForever(autoreverses: false), {
                self.sinOffset = 2 * .pi
            })
        }
    }
    
    init(_ string: String) {
        _chars = State(initialValue: string.map({ String($0) }))
    }
}

struct AnimatedWaveText_Previews: PreviewProvider {
    static var previews: some View {
        AnimatedWaveText("With Friends")
    }
}