Earlier quoted context omitted.
From the apps you mention, except for zoho creator, I feel like are all developer oriented (I can be wrong). In a way, what I want to do is to make apps using spreadsheets as the requirements for the app. What do you mean by 'start application first and not try to theorize it'? Isn't that I don't agree but I didn't understand it well and it looks like somenthing interesting to take into account.
Have you looked at spreadsheetweb.com and calcfusion.com? The former seems mature, with plenty of real paying customers. The latter is new, and I guess they're still working on getting traction.
This looks like real competition, what is good to validate that a market exists.
Thanks for the tip! I would look into them with more detail tonight