2 X for Navionics boating app. I use it on my iPhone and iPad all the time... The USA and Canada map upgrade is $14.99 which is included in the plus version is $14.99 a year but not sure how much detail they have on lakes and rivers so you might want to check that out before you purchase a map.
Cool thing about it, you can connect it to the transducer kit they sell and as you run the areas it actually creates a map for you...
https://www.navionics.com/usa/partners/sonarphone
