The iPhone has become a handy tool for strength training and fitness.

There are many, many apps for iPhone and Android phones and tablets that help you work out, whether it’s strength training, running or just about any other physical activity you prefer.

Here is a selection for your iPhone to help with your resistance and strength training, from weight loss to bodybuilding. Android versions may also be available.

Target Weight for Adults

Target Weight for Adults is a weight tracking app that inspires and encourages as you track your weight loss goals and ideal weight.

Enter existing weight, updates, monitor body mass index and get lifestyle tips. This one is not too complicated and seems to work well as an inspirational and motivational tool.

RunKeeper

RunKeeper is a free app that tracks your cardio activity whether running, cycling or walking. Cardio is useful as one aspect of a weight training and bodybuilding program—even if you aren’t a dedicated runner—because it helps in weight control and body shaping.

RunKeeper is a sophisticated app with many features and functions including tracking your runs, times, calorie expenditure and much more, even heart rate monitoring with the appropriate sensors. Probably the best of its type.

Fitness Buddy

This app is highly rated and offers a free version with more than 400 exercises. It seems to be regularly updated and supported. Fitness Buddy offers the usual tracking and workout help, hints and tools. It has to be one of the best general training apps out there.

There is also a paid version with 1700 exercises and 1000 HD videos for $2.99.

iMuscle 2

Check this one out for $2.99. It has over 450 3D images and animations of a vast range of strength and resistance training exercises. You can learn about muscle anatomy and physiology, create workouts, share workouts, read tips, rotate and zoom images, enter personal details, search for exercises and body parts, and a lot more.

Visually impressive.

There are also Mac OS, Windows, iPad and Android versions available.

FitnessBuilder

Free to start and offering in-app purchases to unlock specific uses, this app has a huge library of over 5600 images and videos, and a vast range of options and upgrades. There are workouts, graphs, plans, nutrition news, expert advice, body and weight tracking, workout progress and web access.

For some, it may be too much to choose from, but it may prove to be a good value for your money if you stick with it.

Full Fitness: Exercise Workout Trainer

This $2.99 app is one of the earliest fitness apps (formally called iFitness Pro) and always gets high ratings. iFitness has hundreds of exercises and stretches with good instruction, as well as a 90,000 item food database and calorie counter function. Track your progress, of course. Nice to use.

GymGoal 2

Buy this app for $3.99. GymGoal 2 is a premium workout helper and tracker with all the main exercises and a database of 52 workout routines to suit most purposes.

The interface is efficient and functional.