The Ultimate Marathon training app: 42K Runner is the easiest and most successful program for training for your first full marathon. With a professionally designed 18-week running program, it takes you from a 21K fitness level to a full 42K. The app keeps you motivated throughout your training, with badges and a log of your runs and achievements. You can easily share your progress with friends on social media and even receive motivational quotes to keep you going. The app also offers features such as music integration, GPS compatibility, and the ability to work both indoors and outdoors. With guidance, information, and answers to common questions, this app is the ultimate marathon training companion.