Yes yes. It's so satisfying contributing to OSM and seeing my changes pop up in OrganicMaps knowing it might help somebody and support open mapping data. I wonder if Wikipedians feel that way.
streetcomplete is a great companion app. It makes it really easy to add points of interest and help collect other data. I've already made over a thousand edits using it.
I always wanted to contribute to OSM but found it a bit daunting.
Any contribution helps! Hell, I went around town just looking for bike parking racks to add, and was able to put dozens of new ones on the map. You can even just label house numbers (with the aforementioned apps listed in the comment you replied to).
To add to that, Maperitive is a fantastic piece of software (Windows only) to create your own custom maps for hiking or cycling with osm. A bit tough to wrap your head around unfortunately, but actually pretty powerful. Hmu if you need quick instructions