Hello Nicholas Ha,
I still prefer pen and paper due to frequent technical difficulties. Here is something that may help you get started:
Natalie aka NAPS 2 B Fit.
You can try the totalcoaching app. It allows you to build training programs and nutrition plans for your clients as well as get live activity reportings, … you can have a 7 days free trial. https://www.totalcoaching.com/
My colleague recently showed me┬áhttp://www.fitsw.com┬áto help me manage my training business. I like it because it’s FREE and has a lot of features to help with managing client progress (cool graphs!), and a lot of features to manage workouts, diet etc. I can even integrate workout demo’s into the workouts for my clients. I’d give you more description of other cool features I use but I need to head over to the grocery store.┬á
The one thing they could work on is the look (not a fan of their colors) but I’m able to get past it with all the features and its ability to increase my efficiency and allow me to manage more clients easily.