If you are looking for free modding options for GTA 5, the community generally recommends reputable, long-standing free menus over "cracks" of paid ones: Kiddion's Mod Menu : Widely considered the safest free external menu with a strong reputation on UnknownCheats Official Cherax : The official Cherax GitHub
If you are looking to "create a feature" for this software, you may be referring to developing custom , which are supported by the menu to extend its functionality. Below are potential features often requested or developed for such tools: Common Mod Menu Features cherax cracked