I think the main part about being free software is not that the code could be reviewed or whatever, but that the software respects its users' freedoms. And for me, that alone is a good reason to respect the software and its developer.
XPrivacy is a great example. Another one would be "Conversations" XMPP client, that is FLOSS, but is a paid app on Google Play. Even though I wouldn't call it completely mature yet (it's 0.7.x and lacks some polish and minor features), it's a good app that does its job very well and 1-5k users (not bad for non-gratis app, I guess) seem to agree.
XPrivacy is a great example. Another one would be "Conversations" XMPP client, that is FLOSS, but is a paid app on Google Play. Even though I wouldn't call it completely mature yet (it's 0.7.x and lacks some polish and minor features), it's a good app that does its job very well and 1-5k users (not bad for non-gratis app, I guess) seem to agree.