I recently upgraded my phone to a Turbo 2 (great phone!) and installed TD HD. The phone is running Marshmallow. The experience has been extreemly disappointing. The app either ignores the press to open or freezes to a black or white screen 90% of the time. I get the failed to respond / report message. It is to the point that I am considering installing Outlook.
I am OK with the UI changes that have been introduced with Venus. I just need it to work! it worked on my old Turbo running Lollipop.
I have been a user of TD since my Droid Razr days and I hope to continue being a TD user, but this has got to improve.