Suggestion by mr X :
Maximum space should be reserved for items. For that, you should remove the line 'List for. . .' from the action bar. Users already know they're looking at the list for a particular trip. Besides, that line can seen completely only in landscape mode. And I'm pretty sure that most users set portrait mode as their phone's default orientation.
Shift 'edit trip' and 'add item' in the space vacated by 'List for. . .' and replace them with icons. Discard 'more' and also the field for entering names at the bottom.
Suggestion by mr X : Maximum space should be reserved for items. For that, you should remove the line 'List for. . .' from the action bar. Users already know they're looking at the list for a particular trip. Besides, that line can seen completely only in landscape mode. And I'm pretty sure that most users set portrait mode as their phone's default orientation.
Shift 'edit trip' and 'add item' in the space vacated by 'List for. . .' and replace them with icons. Discard 'more' and also the field for entering names at the bottom.