CG..... I am not sure what app you seen, there are several to choose from. One that I have on my phone is Navionics boating. It is available on Google Play and the AppStore. It can do routes and stuff and it does a pretty accurate job of keeping your speeds. Here i9s a screen shot of mine this morning here at work. Just slowed down when driving and took a quick shot. The mapping on a lot of lakes is very accurate and nice to. Good luck on your search. Hope this helps.