I've tried using it over the years but I never liked it because there was no information. So last night I looked at my local city and there is almost no information at all. I spent a few hours last night adding buildings and restaurants and removing incorrect items. It was actually kind of fun and therapeutic and I plan to do more of it tonight. My girlfriend thinks it's dumb and I'm wasting my time because Google maps and Apple maps and Bing maps exists but she just doesn't understand open source.
Edit: Apologies, I just realized this question is not Linux specific.
I just use my desktop computer. I've got OSM on my main monitor and Google Maps on the other for comparing. Someone mentioned an app called StreetComplete which lets you fill in data on the map but turns it into a game. I haven't used it much yet though