The Kestrel 5500 is the meter of choice when pairing a ballistics app with a weather meter. In this case, the free Hornady Ballistic Calculator App which features G1 / G7 BC's as well as 4DOF. 4DOF features trajectory solutions based on projectile Drag Coefficient (not ballistic coefficient) along with the exact physical modeling of the projectile and its mass and aerodynamic properties. To give accurate readings, ballistics apps are dependent on local real-time environmental conditions which can differ dramatically from a weather app which gets it's environmental conditions from in most cases many miles away. You can manually enter the environmental conditions into the Hornady app using the standard Kestrel 5500 (non-LiNK) weather meter ($309) or pair the Hornady App with a Kestrel 5500 weather meter with LiNK (Bluetooth) which includes the Kestrel Vane Mount and Vane Case ($399) to automatically import the environmental readings to the app.