Well, the biggest cost here wouldn't be in the app, but in the server infrastructure. As usual with connected apps, people often forget they have to be connected to servers. The app itself is just a view to what the servers provide, so it's not the major cost. 20K $ to 100K $ should be enough.
On server stuff, I expect it to be a lot more, particularly if you aim for a wide audience (several million $).
On a Whatsapp clone, I'd consider:
- solutions for performing calls through servers, not that easy. Look at what Twilio provides. WebRTC is an upcoming protocol that will ease that (web & mobile).
- solutions for API, IM and user accounts management. Look at StackMob or Parse which are MBaaS (Mobile Backend as a Service).
Hope it helps!
The Cost to program an App like whatsapp in its most basic version would be about $5000. In Its most optimum version about $20,000+
http://howmuchtomakeanapp.com is a great resource for checking costs.
I am willing to consult you for free if you are interested in getting an app developed :)
The actual cost for building a service like Whatsapp is mostly dependant on the infrastructure to put in place.
The price for the application (iOS client) is then only a small part of the total cost.
Without knowing the infrastructure choice you made, it is quite complicate to estimate the work load for the iOS client.
The more complex part of such a project would be to manage the message status in real-time, connect to various APIs to enable friend invites to grow the network easily or integrate with their current iOS contact book.
Basically the app cost like whatsapp for iphone is generally between $10000 to $150000. I am suggesting you to consult with TOPS Technologies if you are interested in getting a developing application with high quality and within deadline.
For more details visit at http://www.tops-int.com/outsourcing/iphone-apps-development.html
It depends upon whether you're going to have your own chat server hosted or use a ready framework (like firebase etc), the UI part is not very costly nor the front end functionality but the whole technology in the background.
We created sever chat apps before, and the cost varied from 5 K to 20 K USD because of background tech. only.
This app cost calculator tool is also a good way to DIY, check out http://www.agicent.com/app-development-cost-calculator.
I am glad to consult you (I am a Pro app developer, consulting startups and entrepreneurs mostly).