Takemefishing.org has put out a free Boat Ramps iPhone app. Notice the “free” is not capitalized. The app itself is free, rather than an app that lists where there are “free boat ramps.”
I downloaded the app and checked it out. You can search for nearby ramps based on your current location, by zip code, or by city. There’s a “marina” setting where you can look for marinas as well.
The flaw in the app, if I were in charge of future updates, is that it doesn’t tell you if the ramp in question is a public ramp, if you need a town permit, or if there is a launch fee. It just tells you it’s there.
Most of the time you have a plan where you are launching well before you hitch up the trailer, but it could be a good aid in travel planning to new locations and cities, or if there’s a better ramp in your normal boating area you just haven’t heard about.
To download it, search for “Boat Ramps” in your iTunes account.