I think this has been requested in various different guises and a few work-arounds suggested, but I'll raise this again...
1. What is the general goal of the feature?
To be able to keep a tally of things in a single tap. At present there is the 'spinner' for a 'range' question, but this is a little clumsy in terms of screen 'footprint' and operation. It works well if you only want to count one thing, but if you are trying to keep track of more than one type / category of object, it becomes unwieldy and a bit slower than ideal.
2. What are some example use cases for this feature?
When walking along a path you might want to count the number of yellow flowers and red flowers separately - a tally counter allows you to do that quickly and simply.
Similar for bird counts (if you have a predefined list of birds of interest).
Basically most observational surveys could make use of it. Remember those big clickers that people used to use to check how many people were in a space?
I want to use it for counting the number of features (of different types) on footpaths - pretty specific, I know. I can be trying to keep track of 6 different categories, each up to 20 or 30 items, so need to keep things simple.
I have used an external app called Thing Counter (you can find it on Google Play), but being able to do this with a simple + and - to change the value would be really great (and using field-list layout to have them all on screen) - without needing to transcribe between apps.
I think it might have wide application, but that's just a biased guess 
3. What can you contribute to making this feature a reality?
I will set up an account for beta testing it if anyone fancies giving it a go as a project! I would be happy to mock up layouts and discuss functionality (although, I'd probably just keep pointing at Thing Counter!)
