Thank you Nathan for that clarification.
The link to your description of a PUP is:
PUPs use the mobile platform and trusting nature of users to install an app which might have cool functionality but comes bundled with unwanted features such as draining the battery, leaking data, and aggressive advertising.
The app in that .apk file does none of those things. It simply emulates an industry standard GSM modem, so people can use their android device with software that uses the GSM 7.07 specification's command set.
Thanks for helping me with this.
Chris