MERO is a point-mass trajectory calculator for rifles fitted with SFP/FFP/Fixed scopes equipped with Mildot, MoA or 30/30 reticles. Primarily based around air rifles in the UK, the application has also been used successfully with crossbows, rimfire and centre fire rifles, FAC air rifles. The app is versatile, simple to use, has many long-touch mini-help features (as well as longer help texts) and a basic projectile (mostly airgun pellet) database. A number of Tables and Graphs are included the units and ranges of which can be changed at will. An inclinometer view, having a real-time, heads-up display, is also included.