Hi again Icy!
You definitly makes sense to me!
If you can give people some qualified and ofcourse some sort of realistic advice on how to optimice their workout then there is probably lots of opportunity out there!

Now - to specify my knowledge on this area. I am only 19 years old with a total of little under 4 years of working out with the aim of building muscle (no cardio programs at all). I have never been hired at a gym. Therefore i am really not very informed about this area beside all the talks i have had with the personal trainers and owners of the respective gyms. With all that said. All i have is oppinions and my own thoughts.

Back to you now! What i wanted to highlight with my post was that some of the obsticles an idea like yours, might come across, is that some gyms try to offer their customers more than just machines and dumbbells. When my brother joined his first gym many years ago - there was no sort of personal advice for him at all. He was lucky if some of the old guys would let him in on some ways to optimice his weekly routines.
Thing are different now and people are offered far more guidance and personal advice than they were before. Which might be a problem for a business like yours since i think it is going to be offered even more in the future than it is now. The development we see in Denmark is that - gyms are getting large! Most now offering everything from water aerobics to selfdefense courses which everyone can join from the gym-website. Beside assigning a personal trainer which can be consulted any time of the day. All of this while the monthly costs stays put at 50-70$.
In other words - the gyms are doing everything they can in order to make optimicing and results come as easy as possible.

I still see the potential your sort of idea has though! As i read it you are thinking of making peoples workouts a part of their daily/weekly doings on the laptop? Monituring progress and finding alternate ways of optimicing? It sounds good to me! Maybe if a friend of mine saw it as worthwhile i would even consider paying for it! But i cant tell you what i would pay though. Its hard to say.

Good luck with everything!