Accessing data from non sharepoint Platform into sharepoint

Question

Hello All,

 

There is requirement from customer where in we need to create application where all the users (including non-office 365 users) can access the data from sharepoint(Security should be applied where user is able to see only those items which are assigned to him) .

Also there should be approval mechanism from non-Office 365 can also be able to approve the request without login into the sharepoint environment.

 

Is this functionality Possible