A quick preview of a feature that was in the original (pre iOS7) apps and will be making its way (back) into the new app - Focus on selected topic
By enabling the focus option, everything will be 'dimmed' out except for the selected branches - see below.
Focus is also coming to the Mac app...
...and it works great in conjunction with 'Auto Zoom'...
...coming soon!
NB: There is also an option to 'dim' any 'completed tasks' (i.e. branches where the progress is set to 100%)