Ten Digit Maidenhead Grid Square Locator: https://k7fry.com/grid/?qth=EN72TG11PH&t=h
Public APRS Map: https://aprs-map.info/
Jeromy Alexander APRS Map: http://map.jeromyalexander.com
Visual Topographic Maps: https://en-gb.topographic-map.com/map-nb18/United-States/
Amateur Radio License Map: https://haminfo.tetranz.com/map/AD8GN
airLink Line of Sight Visualizer tool: https://link.ui.com/#
APRS Menolink Current Propogation Mapping tool: http://aprs.mennolink.org/
Tropospheric Ducting Forecast: https://www.dxinfocentre.com/tropo.html
APRS Direct: https://www.aprsdirect.com/
Sun chart calculator: http://solardat.uoregon.edu/SunChartProgram.html