No, I don't mean tie a line to your phone and throw it into the water. Many people don't realize the amount of apps out there to help make your angling adventures easier. Here are some FREE apps that I use on my days out on the water.
Catch Notes - Available on Android and Iphone Catch Notes has really made my trip logging a lot faster and much less of a hassle. I created a template note that I can quickly enter my trip information, then any fish stats that are worthy of their own note. What also makes this app great is the fact that I can attach photos to any note. Most phones today attach GPS data to all photos taken, so I also snap photos of great spots I find on lakes and map them out when I get home (you may need to turn this feature on, check your phones manual on how enable this feature).

Catch Notes Interface
Twitter users will be familiar with Catch's Tags system. Any note can be tagged with a simple # followed by any word to make searching and organizing notes a breeze. I usually tag my notes with fish species, lake names, lure used and any other information that could lead me to more fish in the future.

Notes are easily browsed and searched by Catch Notes Tagging system
Your notes are also backed up by Catch Notes 'cloud' system and can be accessed anywhere you have an internet connection. This is great for the times you want to look up a specific trip, but cannot get to your phone. It also makes it easier to share your information with others... Unless you're a snob and don't want to share!
My Tracks - Available on Android My Tracks is a very simple program that keeps track of trips through your phones GPS. I mainly use it when I am shore or fly fishing and have to get through some nasty areas. It's especially useful when you fish a new area, so you can find your way back... The area around Penn's Creek is pretty uncivilized and it's easy to get lost... Don't ask!

My Tracks interface
Where I use My Tracks when I'm on the water is placing markers at various points around the body of water I am on. It's a great tool to keep track of underwater cover and structure or things you should avoid while ripping across the water at 5 mph... Yes, I roll with a trolling motor people!
Time2Fish - Available on Android Time2Fish comes in 2 forms - Pay and Free. The Free app only goes out 7 days and has ads. Time2Fish uses lunar tables to predict the best times to go fishing. I personally don't use this for that reason. What I use it for is to keep track of the sunrise and sunset times.

Time2Fish Interface Photo: AndroidZoom.com
I have tried almost all of the fishing app's available for Android, but I find these three to be the easiest and fastest to use. One app I wish I could have used was CreelCard, but I just couldn't like it. First off, you have to manually edit the fish and lure categories - which is fine, but it just takes too long to do on the phone. What would make it shine is if you could edit these values in bulk on a PC. It also seems a bit confusing at first and it takes too many steps to simply mark a point.