Any movement is good movement, I find rowing machines are tough movement - good for you!
Just ordered a step tracker you keep in your pocket, didn't want something you have to wear all the time. We're doing a competition at work, and my step counts are super low right now, but by the time we finish hope to get up to 10k a day.
I love guitar, like to fish... both can suck up a lot of time, and neither gives that good of a work out. Exercise, as my dr says - use it or lose it.