I use several.
Wind Finder is great. Pretty accurate. Only tells you the wind which is really all you need. https://www.windfinder.com/#6/39.760/-98.500
Marine Weather by Accuweather is a good app and also a good site on the computer. Click a zone and it gives you the NOAA report. Also allows you to click on the weather stations to get their data. http://www.marineweatherbybluefin.com/united-states/app
Bouy-Weather is a great app with pinpoint forecasts BUT it only does the 2 day for free. The 7 day is another $80 a year. I would probably pay for this app if we had tides.
Noaa's Pinpoint forecast runs only on a desktop and is actually pretty good. Its especially good for someone who doesn't yet under stand how the wind effects waves in different areas. You just click a spot on the map and it will give you the forecast for that spot. http://marine.weather.gov/MapClick.php? ... PTM1uQm6Uk
So for me I pretty much use Marine Weather by accuweather to get me NOAA forecasts and the day before also use Windfinder. There are some that I look at every once in a while but these are my go to.
Watching for Storms a good radar app is very important. Many times the safest way out of a storm is not heading strait back to the harbor but you need to know what the storms doing. How often have you seen a storm coming and look at your phone and either the radar wont display at all or its 15 minutes old or you look from one app to the next and they both show the storm at very different sizes. I will try and keep this simple but the deal is the way these apps work is back on a server the server downloads the NEXRAD radar data and then is processes the radar to make it look pretty. Then sends this processed image down to your phone. Also this image going down to your phone is a very large file so it takes longer to download. On top of that all of this takes time to process which is why most radar apps are showing images that are 10-15 minutes old. And to cap it all off when you are in a storm and thousands of other people are using the same app downloading from the same servers it overwhelms the servers causing everything to slow down more or the apps to not work at all. Not good.
So I looked to the storm chasers. There are a few apps that pull raw data files from the NEXRAD radar stations and not only is this file very small but its almost real time so a radar image that's only a minute old and its fast to download. Also because of the smaller files and no processing if there are a lot of users it doesn't overload the servers. Downside.. You pay to play. The app I use is PYKL3 Radar. RadarScope is also a very good one but I have never used it. Both cost like $10. These can display far more then what most people could ever care to see but what they do show is the most realtime radar data so its a must have in my book. And if you want to get a little more into it you can also see what the winds are doing.
There are 3 radar screens I use most in the PYKL3 app. "Reflectivity Tilt 1" which is rain hitting the ground. "Composite Reflectivity" which is the whole storm from top to bottom. "Velocity Tilt 1" which is winds at ground level.