Phone Apps for lake contours

[dubob]

I have used navionics and found several place that did not match my new garmin. I'm running a Garmin striker 4 on down scan  and running my new garmin 7 sv on side scan and mapping together.  I'm very happy with this setup.
I intend to continue mapping willard bay it is working very accurately.  It does not change when I pass over past mapped areas. It holds my saved spots and is easy to follow.

I'm looking for a phone app for ice fishing only.