"Don't be a dick" has good practical mileage.
The Kantian ideal of the Kingdom of Ends is pretty good one if you formulate it as "Don't use people", but that's too high a standard for almost any business today (especially the ones whose entire model is "using people").
One of my personal maxims is "Lead people not into temptation". In other words, no addictive (engagement) features, no lock-in, don't create dependency, make sure the code you write enables people and gives then freedom and choice (migration/federation etc). Again, those values are almost impossible to maintain in todays climate of hyper-exploitation.