What is a HWID?
HWID (or Hardware ID) is a key identifier assigned to the device by Pushwoosh SDK.
It's a random number generated by the first application with Pushwoosh SDK installed on the device. It's later shared with other applications which contain Pushwoosh SDK so all such apps will have the same HWID as a result.
However, if the user deletes all the apps with Pushwoosh SDK and then re-installs some, a new HWID will be generated once again.
Android HWID example:
IDFV is being used as a HWID of the device. It won't change as long as there is at least one application from the same vendor installed on the device.
iOS HWID example (only upper case!):