I could not log into my account using Doit.im for Android, but I could with the older version Doit Pro. It turns out that when you hit return after entering your password using the latest Doit.im for Android it adds the return to the password instead of submitting the login details. You can't see the return added but it gives a message that you have entered wrong password. If you don't hit return but click done instead you can log in normally. The same process using the older version pf Doi app does not do this and hitting return logs you in.
Thought you might look into the reason for this bug.
I am using an LG G4 smartphone with lollipop android system.
Kind regards,

Lewis Walch