I have been using RunKeeper for several years and love it. They have built in training plans if you want to use them. I have tried several others but keep going back to RunKeeper for its ease and simplicity.
Running by Nike is what I use. You can use your phone or purchase a GPS running watch which is nice to see your pace, distance or any other stat while on the run.
I've been an avid runner since elementary school (started in track) and have been running ever since. I go for a run pretty much every morning (while it's nice & cool) and I like to use the Nike app. I've used it for years and it's worked really well for me. You can use different settings for time, distance, etc. It gives notifications after you run so many miles, the half way point and when you're close to finishing (which I find makes it easier to know how much farther I have to go). It tracks your pace, which I like because I try to run at a certain minimum pace and if I catch myself slowing down too much I can know that I should speed up. At the end it tells you how far you ran, how long you took and your average pace throughout. It keeps record to see if you're improving.
May be a bit late for this but I just launched an 5K Trainer app on the store which is perfect for beginners. Let me know what you think, always looking for feedback
I have friends that use the Nike+ app & compete with each other: https://play.google.com/store/apps/d...m.nike.plusgps
Also Spotify's running mode is pretty legit. Increases/decreases the tempo of the song to match your running pace.
I use multiple apps for my power walking. S Health is my go-to app. I do use Google fit because I do have a Moto 360 2nd gen. There is also MapMyRun which alsi works with android wear.