I gave it a quick try and:
1. I find it counter-intuitive. I was expecting something like cryptrader.com, but whatever I do I am sent around in circles. Clearly I won't put API keys in just like that, I wanted to see various exchanges all in one view without them.
I open trading terminal, I am sent to a presentation page, I am asked to sign up although I am signed in and if I press sign up I am sent back to main view.
2. As long as it works for free with known disposable mail addresses, nobody will pay those 4$/month.
I guess that you should work on improvements first. (And for API keys, trust has to be built in time).
Why would I also pay such amount for money for a service that I have been getting free for a very long time now with Tabtrader, I have been enjoying this Services for years now without any form of disappointment, and Tabtrader has most of the great exchanges you can think of, where you can pull the API easily for one to have access to all the coins on them and also be able to trade easily with it.
Well, since he has trial version of it first which is one of the best way to convince people, one could give it a try and see if he has anything that is different or better than that of tab trader, I just hope he will not ask for my credit card details before trying it, because that is the one that will piss me off the site already, but if I can test it and it gives me more functions, I will try it.