GA instructor with student pilot reported an NMAC near VPPIR fix while returning to GEU airport.

Narrative

My student and I were returning to GEU from the Rainbow Valley Practice area; we made our position reports in the practice area and then switched frequency to GEU Tower to make our initial position report over VPPIR. After making our initial call to Tower the Controller stated that there were two aircraft at that position; one at 2;500 feet MSL and one at 2;400 feet MSL so they asked us to IDENT. We were searching for the other traffic and we spotted it at about our 8 o'clock position. The wifi inside the aircraft was spotty so we did not pick up the other aircraft on our foreflight until we had spotted it visually. VPPIR is a point where two of the practice areas end and pilots often switch onto the frequency of the airport they are flying into. The other aircraft was not on frequency with GEU but they appeared to be traveling to GYR. We did not hear any callouts on the practice frequency prior to switching frequency to GEU. We broke right and continued away from the other aircraft which did not appear to deviate at all.