As far as i know , you dont need an android client to register. You can just use your browser. Take the web.telegram in browser and you are good to go. And it doesnt need a plugin or a specific browser. Even N900 browser will be able to do it. I personally repect the providers who give a web interface alternative to their applications. If you dont have time to develop clients for all the different oses out there , give a good web interface. It is as universal as it can get.