Creating an iPhone-friendly gamepad is a perpetual challenge, but Justice Frangipane has come up with a new design to step things up in this market.

While game controllers for iPhone are no longer a rarity, the space leaves plenty of room for innovation. Frangipane's project aims to prove how things can get better in this area, and the company has come up with a sleek iPhone case that holds a Bluetooth 4.0-enabled video game controller. Moreover, Frangipane's controller recharges via solar power.

The project launched on popular crowdsourcing site Kickstarter on Saturday, Dec. 22. Frangipane has been working on this concept for the past one year, and has now teamed up with iDevices, the creators of the Bluetooth iPhone meat thermometer iGrill, to transform the project into a real product.

Frangipane's gadget sports a controller that snaps into the back of an ultra-thin iPhone case, providing physical controls compatible with specific games on iOS, supporting Bluetooth accessories. As previously mentioned, the device charges via solar power, and it can also use "trickle charging" to sip on low light, as well as indoor light sources.

The use of Bluetooth 4.0 Low Energy technology allows the device to work without sapping too much energy which in turn will help it connect to the iPhone without draining the battery. Consequently, the controller should be able to provide four hours of play time on a full charge, without any light source.

Furthermore, Bluetooth 4.0 also means that response time is significantly improved. According to Frangipane, BLE has a six millisecond response time, compared to a sluggish 100 milliseconds for older Bluetooth specifications.

The company further notes that Apple is on board with the project, and, thanks to help from iDevices, the Cupertino giant has in fact agreed to work with the team to ensure the controller works with iOS devices.

According to TechCrunch, the prototype "still looks like something created by a home hacker in a garage" at this point, "but it clearly demonstrates that the concept works." Frangipane promises to have the control pads snap into place on the front of the device in the case frame by the time it ships, and to have the wires or connectors less exposed.

Those who back the project on Kickstarter can get shipped devices for $60, with an estimated delivery date of June 2013. Meanwhile, the $500 pledge level opens up 125 prototype testing spots. The Kickstarter campaign runs through Jan. 15, and the team aims to raise a total of $135,000 to bring the product to the market.