Running apps like Runkeeper, Nike Run Club, iSmoothRun, Endomondo, Runtastic, Map My Run and Stava all help you keep track of your training. That is important because over-training (doing too much too soon) will definitely lead to injuries. Plus they run on all smartphones and each has other added features.
Which One to Choose?
For the the most part they all do the same thing. So you should download the free versions of several and just check them out. You looking for something easy to use. Just remember, you probably won’t be looking at it during your rub, but a lat after you run.
But the biggest reason to choose one over the others is social media. Even though running is mostly a solitary activity, you can still benefit from social contact, especially new runners.
That’s shy I use Strava. Several of my good friends use Strava, and I don’t know anyone who uses the other apps. You might know if your friends use an app, but most apps can check your address book to see. Some of your friends might surprise you.
A word of warning though – if you decide to get a running watch, one that tracks your location (GPS) and maybe even your heart rate (HR monitor), they don’t always play nice with running apps (because they probably have their own app or website). But usually there is a way to ‘sync’ them together, you just have to look for how to do it. Or you can do like I do and just run them at the same time.
PS. I haven’t put any links on the page for these apps. I figure you can find them yourself on the Apple Store or Google Play on your smartphone!
Apps I Recommend
Strava

Track your fitness activity with Strava. Record your run, map a cycling route & analyze your training with all the stats – for free!
Whether you’re training for a marathon or simply love taking your bike out for a ride, turn your smartphone or GPS watch into a sophisticated tracker with Strava. Join millions of athletes and active people and reach your fitness goals!
I like Strava and used it a lot before I got my first Garmin GPS watch. But I like it now because several of my family and friends use it and I like that I can support them and they can support me using the social aspect of their website. My Garmin location data and heart rate ‘sync’ up to my profile on Strava just as if I had run using their app. So, it’s easy to stay with them.
Nike Run Club

Nike Run Club has the tools you need to run better, including GPS run tracking; audio guided runs; weekly, monthly and custom distance challenges; customized coaching plans for your goals; and nonstop motivation from your friends. Reach your goals and have fun along the way with Nike Run Club.
I actually started my running journey with the Nike (using their website before ‘smartphones’). This app is pretty simple and straightforward, especially if you’re just starting out. I now am using it because of the audio guided run feature it has. No other app has anything like it, and it’s free.
iSmoothRun

iSmoothRun is the best App to effectively track and log all of your running, walking, hiking, cycling and any other fitness activity you like. Solid performance. Continuous development. Best sensor and external display support.
This is another app I’ve used for a long time. While all the others are big companies with tons of developers and owned by even bigger companies, iSmoothRun is one programmer who happens to be a runner too. The app costs a one-time fee of about $5 but that’s for life, so not too bad. Plus, it is a stand alone app – all the data stays of your phone (unless you ‘sync’ it up with one of the other app’s websites). It’s audio feedback is pretty good, there is a way to program it to do all sorts of workouts using distance, time, heart rate, pace and even intervals. One reason I kept using it is it also has a run walk audio feature I used a lot when I was getting started. Well worth the $5.
Runkeeper

Reach your running goals with the ASICS Runkeeper™ app. Track exercise, set measurable goals and see progress along the way—whether you’re just getting into running, training for a race or trying to PR, we can help.
Endomondo

Get the most out of your runs, walks, rides, and other workouts with our top-rated fitness tracking and personal training app. Track your workouts using GPS, analyze your stats, reach your fitness goals, and be part of our global community of millions of fitness enthusiasts and athletes. Download the app now and get motivated to get active!
Runtastic

Ready to start your running & fitness activities? Lace up your running shoes and track distance, time, speed, elevation, calories burned and other stats with the Runtastic running app.
Map my run

Track and map every run with MapMyRun and get feedback and stats to improve your performance. Discover the best running routes, save and share your favorites, and get inspired to reach new running goals with a community of over 50 million runners. Whether you’re a beginner looking to log your first mile or a seasoned runner, you’ll find the features and tools you need to stay on track and motivated along the way.