I have seen the question How Android Support Library work? however it does not answer the question of whether each app that uses the same support library causes the duplication of code, and thus uses up space on the device. For example, if the support library is 1MB, and 7 apps use it, does that use an extra 1MB or 7MB, or some other amount?
Also, if my app uses only part of the support library, does all of it need to be installed on the device?