I still have my old phone since it has at least one paid app on it that was removed from the Play store. I can't download the app I paid money for to my new phone, but I can still use the copy installed on my old phone.
Realizing this has completely dissuaded me from spending money on apps, but that's a whole other thing...
In my case it was a music composition app (Xewton Music Studio) that used to have both Android and iOS versions, but then some other company bought them out and discontinued the Android version.