I tend to get around a bit in fitness related things, so here are my personal reviews of different apps that I actually use and gyms I've tried.
My Fitness Pal
What's it good for? Mostly it's a calorie counter that lets you log in what you eat. Great because it can scan bar codes and let you put in exercise.
It's a fitness motivator, by giving you points for exercising which you can rank against other people and win badges etc. Great if you have friends you want to compete against without being able to meet up in person.
Runner's World Smart Coach
This didn't get its own post, but the pros and cons are discussed in my half marathon training update as I move from Half Marathon Coach to this.
Virgin Active Health Clubs
There might only be a handful in Australia, but if you want a gym with all the bells and whistles, this is for you.
All female, which is great if you are intimidated walking into a weights room elsewhere. Also nice level of luxury so it feels like a treat.