A group of developers over at teslamotorsclub have been working on adding support for an iPhone / Android App to the Tesla Roadster. We've come up with a solution known as OVMS.
The system gives you monitoring of the car from Android and/or iPhone (and iPad, iPod Touch) Apps, including SMS or PUSH notifications of charge interruption. You can even set the charge mode and current. And, it is available **today**.
You can find details at
A summary of the project is that the Open Vehicle Monitoring System (OVMS) is three things:
1] A low-cost module that fits in the car. It is powered by the car, talks to the car on the CAN bus, and uses the GSM cellular network to talk to its user.
2] A server. The car module can be configured to either talk to the server (via UDP/IP or TCP/IP over the Internet) or the user directly (via SMS).
3] A cellphone App. This talks to the server (via TCP/IP HTTP protocol) to retrieve messages from the car and issue instructions.
Part  is all that is required. You can use a cellphone and SMS messages to talk to the App. It requires a SMS messaging plan on the SIM card in the GSM modem in the car.
Parts  and  provide a much more seamless and powerful experience, but are optional. They requires a small data plan on the SIM card in the GSM modem in the car.
Even if you choose +, you can still use  as well (for initial setup as well as ongoing on-demand).
The entire project is open source - from the hardware schematics to the APIs to the car and server firmware. Everything is published on github. The purpose of this project is to get the community of Tesla, and other, tinkerers to be able to expand the project. We can't do it all, and there is so much to do. What we are doing is providing an affordable and flexible base that the community can work on and extend.
Everything is open, and APIs are public. Other car modules can talk to the server, and other Apps can show the status and control the car. This will be a foundation that will hope others will interface to and and build upon.
If you have any interest in participating in this project, please contact us at www.openvehicles.com.