https://apps.apple.com/au/app/bit-map/id1560781471
(I think it should also run on AS Mac as well (but not Intel Macs), but I've not had an opportunity to test this yet.)
For those who don't know...
Bit Map was the first iOS mapping/navigation app to provide users with the means to use their own arbitrary maps on their iOS devices (in 2009). At the time, other apps only worked with maps that were specifically designed for the app, or with maps that were built into the app. With BIt Map, you can use any map image, such as a photo or scan of a paper map, and georeference it on the device, or use a raster image that is already georeferenced.
Bit Map was later replaced with another app, and that app was later sold to another developer, who sold it on, and it was never updated, and that other app no longer runs on current devices.
So Bit Map has been re-written from scratch, and includes all the features of the previous version and the other app, as well as several improvements, the most significant of which are:
- Use of online map services, such as WMTS, TMS, XYZ. (Has Open Street Map configured by default.)
- Can read vector data from many different formats, and can write to several formats as well, including: GeoPackage (default), Shapefiles, GPX, file geodatabase (read-only), KML.
- FOUR methods of georeferencing raster images, now including arbitrary control points
- Highly customisable layer styles (symbology)
- Lots of options for sharing data, maps, styles (AKA symbology) and settings with other users
This new generation of Bit Map is more of a GIS with a mapping/navigation focus. Some of the features planned for future releases include the ability to create/edit polygons and lines. At present, polygons are read-only and lines can only be created using the tracking feature. This GIS approach means that there is a little more data-management overhead than earlier versions, but it is much more flexible in what it can do, and the maps that can be displayed (ie, multiple rasters, plus multiple vector layers can be displayed on a single map, in which-ever layer-order is desired.)
The Bit Map home page is at: http://nixanz.com/bitmap/
The (almost-but-not-quite complete) user guide is at: https://nixanz.com/bitmap/user-guide/
Enjoy!