Remote Facial Attendance Access

I already run an Android-based attendance app that authenticates a user only when the handset is physically connected to our office Wi-Fi (Network A) and a live-video face scan succeeds. I now want to leave that phone on-site, still logged in to Network A, and operate it from another location... (Budget: $250 - $750 USD, Jobs: Android, Face Recognition, Facial Recognition, iOS Development, Mobile App Development, Network Security, Video Streaming, WebRTC)