Anyone with an Android phone and a Raymarine Dragonfly Pro 4 or 5 can connect via Wi-fish and create your own charts. This is huge if you fish an area where maps may not exist (local pond or lake, backcountry, etc). Just go fishing, run your unit as usual and watch the bathymetrics build in on your phone.
I have done this and found several humps and holes I never knew existed. And I've been fishing this lake for YEARS.