I don’t do a lot of ‘on the go’ mapping. I have tried a lot of the tools out there that should help me do that: KeypadMapper, Go Map!!, Vespucci, Pushpin, OsmAnd. Most of these are way too convoluted for me. When I am out and about, I just want to make a quick edit - usually a POI of sorts - and move on.
Pushpin and Go Map!! come the closest to what I want. Both are available for iOS only, I think. (Do Android users not like simple editing tools?) They let me quickly add a node and upload it to OSM. Or add some tags to an existing one.
Still, what I end up doing most is just taking pictures with my phone. Lots of them. I try to get both overview and detail. I end up with a collection of images like this one here from right before I moved to the US.
When I get home, I copy all the images to my computer and load the entire directory into JOSM. It will put the image locations on a map. I can cycle through them easily and map what’s on there using all the convenience of JOSM.