Bitchat: Decentralized peer-to-peer private messaging app

Do relays have to be running a bitchat app in the background to act as relays?

// From the message handling code:
// Relay broadcast messages
var relayPacket = packet
relayPacket.ttl -= 1
if relayPacket.ttl > 0 {
    // Probabilistic flooding with smart relay decisions
    let relayProb = self.adaptiveRelayProbability
    
    // Always relay if TTL is high (fresh messages need to spread)
    // or if we have few peers (ensure coverage in sparse networks)  
    let shouldRelay = relayPacket.ttl >= 4 || 
                     self.activePeers.count <= 3 ||
                     Double.random(in: 0...1) < relayProb
    
    if shouldRelay {
        // Add random delay to prevent collision storms
        let delay = Double.random(in: minMessageDelay...maxMessageDelay)
        DispatchQueue.main.asyncAfter(deadline: .now() + delay) { [weak self] in
            self?.broadcastPacket(relayPacket)
        }
    }
}

If so, this relies upon network effect of people joining the network to help it expand