People intuitively understand you when you say you try to go to locally-owned co-ops/farmers markets instead of Walmart when you can, right? Or that you prefer to avoid Amazon and support your local independent bookshop, right? It's actually cool to care about these things, people respect you when you make little rebellious political decisions.
My advice is frame your decisions about what apps to use the same way. "I try not to use the big corporate-owned apps when there are smaller non-profit alternatives run by communities of normal people." Now you're not some paranoid weirdo who's afraid the NSA is out to get him, you're just socially-conscious and care about things like where your time and money is going. I almost never try to explain what "open source" is or anything like that.
A girl on a first date once asked me what messaging apps I used and I said something like "My friends and I have been using this smaller non-profit app, it has all the same features as Messenger but without all the Zuckerberg bullshit." and she downloaded it right then and there, thought it was cool.