It should be, but apps can create custom Intents anyway (for example, com.facebook.(katana|orca) definitely has custom Intents). It's closer to scanning what fo

It should be, but apps can create custom Intents anyway (for example, com.facebook.(katana|orca) definitely has custom Intents). It's closer to scanning what fonts you have by webpages though: they can't enumerate what packages you really have but they have a huge lists of these custom Intents to scan.