Open-source aviation mapping program, no-nonsense basics with minimum bells and whistles. Includes geo-referenced airport diagrams and approach plates. Source on https://github.com/mrieker/WairToNow

App covers areas covered by US charts, including sectionals, terminal area charts, helicopter charts and what's left of world charts. Also included is mapping via OpenStreetMaps for walking/biking to nearby $100 hamburger stands, as well as georeferenced approach plates and airport diagrams. Also provides OpenStreetMap-backed runway diagrams for all airports, though they are primarily used for those airports that don't have official FAA-provided airport diagram plates. Approach plates include an optional on-screen DME display that the user can configure.

Also covers parts of Europe using charts from https://www.openflightmaps.org and provides access to plates from Eurocontrol. The Eurocontrol plates are not geo-referenced but you can manually input your own geo-referencing information for plates you anticipate using.

Server provides scripts to populate and operate a server, fetching the required data from online sources. The scripts should be run every 28 days. Server code available on https://github.com/mrieker/WairToNow if you want to set up your own.