Is it possible to change Notetype on many card at once. I have looked at Card brwser but there only Undo Change Notetype 
Not in AnkiDroid (AnkiDroid 2.16 User Manual), but there is in AnkiDesktop (Browsing - Anki Manual). Even if you could do something like this in Droid, you’d probably want to do it in Desktop, because it will be easier to manage.
Hi, could you give the following a 
reaction so we can prioritise interest in planned features for 2.18: