I had an app idea in 2014, so I had to learn Objective C on my own and mostly here.
After 6 months the app was out.
It has been followed by 3 other related ones.
Then hired by different people having ideas that would never come out.
However that lead me to be hired as iOS developer.
Jumped on Swift as it came out. Loving it, until...
I had the Notch app idea which was Nōtch at first... iPhone X came out 2 weeks and a half after my first submission but the app was stuck in review since then and until Notch Remover came out... While I had to clone my own Nōtch to be Notch and submit it for review while the original was stuck it got approved 8 hours after Notch Remover which took advantage of all the hype. Nice one!