If you simply cannot pay, use a different, legitimately free app:
Instantly converts between Geodetic (Latitude, Longitude) and Cartesian (E, N, Z, Orthometric Height) coordinates. Mobile Topographer Pro Mod Apk
The "Pro" version removes the limitations of the free version (such as point number caps and watermarking) and unlocks full GIS capabilities. Typically, the official version costs between $15 and $30 on the Google Play Store—a reasonable price for professionals but a barrier for students or casual users. If you simply cannot pay, use a different,