If you own a Samsung device that you mod you are probably familiar with Odin. Odin is used to flash stock images to your phone incase you have bricked it, or if you just want to put your phone back to stock for warranty purposes. A while back developer "Chainfire" released a app called mobile Odin which allows you to flash stock images without a PC directly on your phone.
His latest creation "FlashFire" allows goes even further by allowing you to flash custom roms, and some mods to your Samsung device. This means you are able to flash roms without having an unlocked bootloader, or even a custom recovery. The only drawback here is you won't be able to flash and AOSP roms since you can only flash roms based on the Touchwiz kernel. This is still a beta product and you will have to join the beta program to download and install the app. Head to the link below for more info.
via XDA