Not parent, but for me it is because signing in with my google account is a relatively bigger commitment. They have my email, they can send me marketing content, among others.

On the other hand, I still have no idea what their product does uniquely outside of any todo list. Thus, there is no value for me there outside of the proposal of "Deep Work" which I remember fondly due to the book.

In simple terms, signing in with my account extracts an imagined cost (A company(?) has access to me), and the value presented is not enough for me to justify that cost.

Adding other screenshots, and descriptions of what the application does would allow me to understand what I am getting into, before deciding if it's worth it for me to pay that cost, and thus make an informed decision as to whether I want to sign in or not.

Signing in gives access to user data. In return there should be some utility to the user. If there is no implication of the latter, the user won't give away the former.

Because you pay with your data just to see what the thing does. If you really wanna do that, allow at least email.

I also feel the same. I want to see how it works before giving the creator my email.

So, I ended up not signing in, and, thus, I didn't learn how it worked.

The product sounds interesting, but I'm not going to link my account unless I can see that the product is legit. i.e testimonials, screenshots, a navigation menu that doesn't just point to home etc..