Good running app?

ewicc

runkeeper is another one you can use.

parking_question_chap

Not really sure how an app will make you run further.

Call me old fashioned, but fitness improvement comes about by pushing yourself that little bit harder or further each session. If you are struggling it might be an idea to get a playlist and listen to that when you are running.

If you have not already, you will be better spending the time in a running shop and getting a pair of trainers that has been assessed by an expert as the best ones for your gait. This usually involves recording you run on a treatmill and then test running a few pairs.