Is there any app on cydia that will make it so that i can use an "unsupported charger" to charge my phone in my car. I would rather not have to buy the $30 adapter...
Try Popup-Blocker from Cydia. It blocks/ stops a lot of the warning/ "uncompatible" popups you get from old/ unauthorised hardware. These are listed as "Accessory Warnings."
. It works with my incar hookup and an older dock I use in my kitchen to charge/ listen to music and watch video.