Can I login to two Encyro accounts at the same time?

Yes. 

When logged in with one account, you will see the current email address used for login near the top right corner of the Encyro web page (on a mobile phone or a small screen, you may have to click the menu icon in the top right to see it).

Click on that email address to reveal a drop-down menu and click "Add Login." You will then be able to login with an additional Encyro account.