1. I have no information on limits of storage.
2. Privacy page is really non-descriptive on a few important topics.
3. End to end encryption is a must. I see no mention of encryption at all.
4. The design hurts my eyes.
5. There are no screenshots of the user interface to interest me in it.
6. There is no pricing information at all.
I could go on. I recognize that this is in it's "Alpha" stages, so just take this as a list of things I think it would be good to improve on just from a first glance. I honestly would not even be interested in testing it unless it had end-to-end encryption (including at rest) that only I have a key to decrypt. This is because I honestly wouldn't want to use it without.
I also just want to mention that there are other services similar out there. For instance, box has notes built in (not a separate app) and you could even just host your own next cloud that does all of the things you mentioned so if you are trying to go in for a profit... you're going into a really crowded market.