The main thing is: don't download a third or fourth meditation tracker hoping that one of them has something "right" in its algorithm. It'll only make the effect stronger - the more apps you use, the more often you check notifications, the more coincidences you'll notice. It sounds logical that there's some hidden meaning, but really you're just increasing your sample size of random events.
A friend of mine got into numerology a year ago and bought an app to track "synchronicities" - like he'd record what time something happened. So he convinced himself that 14:37 kept appearing in his life constantly. In reality, he just started looking at the clock twice as often and only remembering the moments that seemed "significant." When I asked him to show me the statistics for a month, it turned out he'd completely missed a bunch of other combinations and basically cherry-picked the ones that looked like a pattern.
What they describe in the neighboring answers about apophenia - that's exactly it. After meditation you're in a relaxed, sensitive state, and your brain isn't working in "critical" mode. When you open notifications and see 11:11 - it "sticks" in your memory. But when you see just 14:23 - you don't notice and forget about it a second later. The app has nothing to do with it; it just sends notifications at regular times. If you want to check, track all notifications for a week straight, including the "boring" times like 13:42 or 15:08. It'll immediately become clear that repeating digits don't happen any more often than they statistically should.