if you are a working person with little time and need to work your fitness up and can't afford a personal trainer I recommend the FREELETICS work out program that's available as an App in Itunes (I assume also for android phones). These are timed short intense workouts (high intensity interval training). The idea is to do short excercise routines at maximal effort followed by a brief recovery period and then move on to the routine which focusses on a different muscle group and then repeat excercises over multiple times. Excercise science has shown that this is a fairly efficient way, to train cardio, muscle and stretch soft tissue...
While this concept may not be entirely new, here's the kicker...the app and many routines are free but if you sign up for the virtual coach you will get a tailored program that will integrate workout programs with recovery periods. After an assessment you will start out and then after each session you need to answer a few questions that the virtual coach uses in addition to the recorded times to assess your progress as well as custom fit the next sets. The other big benefit is that the regular "Bodyweight" app does not require a gym or any equipment so it's basically so all you need is a small space and your phone app to record your progress.

My nephew visiting from Germany where it's been gaining traction showed this app to me a few weeks ago and I have just started using the app and have to say I love it. I had been road biking and MTBing the last few years to stay in shape but was wiped out after a few excercises and had my heart pumping pretty wildly.

Besides the "Bodyweight" app, Freeletics also offers a "Gym", "Running" and "Nutrition" app. I am also trying the running app but probably won't use the coach feature much with it. I also like the nutrition app. I had a cardio event a few years ago and my wife also has elevated cholesterol so we have been working up our diets a bit to move away to greener food. I have been using the app mostly to compare notes with our diet and get ideas for dishes.