my favourite couch to 5k app so far is Run Double Couch to 5k which is available here http://www.rundouble.com/home its for android and Iphone users - I am currently using the android version on my LG G2 phone. I then bought one of thes fab Tune armbands to hold my phone in, slightly higher price than a bargain on ebay but great quality comfort and usage. please visit AMAZON for more phone choices
some pics from the rundouble app
example 1 - my run history
example 2 - a detailed breakdown of my run, the map of it and all my times. handy to look back on and see how well you are doing.
you can do all kinds of runs with the free app, timed, distances, intervals etc. i am currently up to week 5 but have just started running with a friend and we do some interval running, an example would be 5 mins walk to warm up, then 2 mins run, 2 mins walk, repeat the run/walk 6 times then cool down walk for 5 mins. you can also leave it open ended and keep walking. it also lets you listen to your music and dims it while it gives you run and stop instructions, its also possible to use your camera, take phone calls and text while doing a run.
This app will sync with Myfitnesspal and Facebook, which in turn then syncs to my fitbit flex. i have just pre-ordered the new fitbit charge HR as it has a heart rate monitor connected for more accurate calorie burn. available from Amazon
so even if you are a beginner like me or a pro wanting to run more than 5k (there is a 10k app too) get out there and have some fun. i have taken some fab photos while i run