I need a very basic app built for my customers mobile phones. I send between 1-10 messages per day by e-mail using a mailing service however, I would also like to send them messages to their mobile phone. I need the authorizations to be done via my website which means that only users who are registered on my Joomla website should be able to log into this app and receive messages. I have between 2k-10k users so it is very important that this app works correctly when sending bulk messages. It must be iPhone compliant. This app does not need to be very fancy however I would like for there to be my logo and icon.