This isn't what you think it is. It's definitely not an excel competitor. It feels like a cross between an Access and a Salesforce competitor.
It looks like you're close to making a good product. But you're at 90%.
Basically I tried creating a little app and it's very painful. I don't believe you've sat with a user and watched them try to create an app without you intervening and giving guidance.
So sit down with some real users and watch them try to use it. Your front page claims install>customize>import. It doesn't work like that at all. It was confusing. For example the upload excel img looks like it's a button. It's not. When I did manage to create an app I first tried editing the cells directly, but they're not cells like excel. Eventually I realized I had to add a textbox, which was also confusing as the width kept changing and I couldn't stop it. At about this point I gave up. Then got hit with multiple alerts when I tried to close the pages.
Then tried to save it.
The most confusing save mechanism I've ever come across.
Tried to just close the page again. Multiple warnings again.
Argh.
And calm. I'm in the process of stopping smoking so my temper is a little, hmm, Hulkish.
I decided to try again while writing this using the import excel function. It didn't work from the front page at all as you had to already have a project (why?). When I tried to do it via the upload the open file dialog never opened. I gave up again.
Also find someone who knows something about sales and marketing. There's not even a CTA button on the homepage to signup. The copy is terrible. You've made the mistake of going typical corporate million page website which doesn't actually tell me anything at all. The order of the home page is all wrong (you should not be leading with the app concept which doesn't actually seem to be in the product). You're making the mistake of selling features, not benefits.
I'd personally spend a little more time so the sales website didn't look like bootstrap (the irony being you don't even seem to be using bootstrap).
As I said, good, but no cigar yet.