I'm in the middle of week 6 of 9 of "Couch-to-5K". I can't believe how well it's going. I have never been a runner. I was so sure I would have to repeat weeks, but I have not. I'm trying to use the "natural running" style of running and I have light shoes for that with minimal heel rise. I was concerned about the first long 20 minute jog, but I did it !! 
My dogs are also enjoying coming along with me and they're probably getting into better shape too, although they want to go faster and longer. Ha ha !! Part way through this program, I signed up and paid to take part in a local 5 K run, since it said it might sell out. I was not at all sure I would be able to do it. It will be a "Resolution Run" on December 31st, about two weeks after my scheduled 9 weeks is supposed to finish, on December 13th. I figured that would give me a bit of a buffer in case I had to take it a bit slower.
I tried to take up running a year and a half ago without the help of an app and I really couldn't do more than about 20 second jogs at a time. I have been doing other things, so I was probably in somewhat better shape before I even started this time, but I'm still amazed I'm actually doing this. A few of the jogs have been a bit tiring at times, but it's sure working for me. I have been able to do all of the jogs without stopping or walking when I was supposed to be jogging ! Hooray !
In the last week or two, the novelty has worn off a bit and I don't always feel like doing these workouts, but I have so far always managed to get myself to do them. I have taken the jogs at a reasonable pace, not trying to push myself too much, since I wanted to be able to do them, so I haven't been too concerned about the distance that I'm going. Some days, however, I push myself a little more if I feel like it.
The zombie trainer has been kind of fun.
I'm thinking that if I can do the 5K, I might go on in the spring to try "5K to 10K", then enter the Mother's day 10K. Having goals of specific races seems to help !
Since it's winter and there's snow and sometimes ice here, it's not always the most secure footing for running. I have not slipped on anything so far, but I'm a little concerned about that. I don't want to hurt myself or fall.
After I finish "Couch to 5K", how much or how often would I have to keep running to keep up what I've accomplished so far, say for the next couple of months, January and February, to possibly start the "5K to 10K" in March, so I would be able to run the 10K race in May ? Should it still be 3 times a week of about 30 minutes / 5K ? Or would less often afterwards be OK ?