I threw together an app for calculating range/bearing/elevation/eta for Artillery (mortar & vehicles). Either put in your position (4 digits, so take the 3 from the map and rough the 4th - So if you’re 3/4 the way across grid 025, then 0257) and it will calc range & altitude difference, or enter range and altitude difference directly (using map tools for example).
Pick the arty type and charge/range and it should give hi/lo elevation and timings.
Any feedback appreciated.
Its a responsive web app so should work on destop, tablet and mobile.