I'm a bit behind the times with smartphones. I only got my first a couple of years ago, a small-screened, low-powered model on a cheap-ish contract. It did the job, but I recently upgraded to a far more powerful, larger-screened model with 4G capability and WOW suddenly I'm finding I can do all sorts of cool things. One of those things is OSM-ing on-the-go with Vespucci. I'd heard about it ages ago but dismissed it (who'd want to fiddle around with a phone when you can sit at home with JOSM?), but I installed it recently and it's brilliant. Smooth, intuitive, & great features like the "recall last tags" button and the fact it won't let you download new areas without finishing off the last area. I've become a father recently so don't have time for long hikes in the country right now, so instead I'm doing small things like POIs and addresses whilst walking to the station, and uploading them via Vespucci on the train to work. Perfect.