I may be the last guy out there to have realized this. But a fishing buddy of mine told me about the Navionics app on his I phone and I kinda blew it off cuz I have it on my boat...until my power failed on my Lowrance and next thing I did was download it for 10 bucks and man was I blown away. The detail of the contour lines and all the features. You can even mark way points and leave track lines. CRAZY! anyways thought it might be a help to someone out there.

Yeah - I use it for my gps while at the lake. Have all my waypoints and everything else on it. Worth every bit of ten dollars!

Checked this out at the iTunes store; the price seems to have gone up to 14.99 and the reviews are pretty bad; >1/3 rated it lowest, with issues like accuracy and stability.
Do you know if it's been upgraded to fix the reported problems?
One big issue seems to be that it sucks up a lot of network usage, which if you have the minimal data plan might be costly.
Any experience with these problems?

In any case-- seems like a good back-up but maybe not a cheap replacement for the navionics chip.....(duhhhh)?

well it was still 9.99 when I checked and I don't know about usage cuz I have unlimited and I didn't think about that...but as far as accuracy I was out again today with rooster and I showed it to him on my phone and compared it to the unit on my boat and it's pretty spot on as far as I can tell. Another cool use is just sitting on your couch you can scan a lake for humps and points that you want to hit and mark points. I don't know if there is a price difference for I phones and android...I have droid. But it is definitely a good back up plan.

by the way we went out today up north but not up the river and caught 2 fish...one 5 and one 16...so it was a good day. One on a Gizzard on a board and the big one on a trout freelined.