After deciding to stop making iOS apps after twelve years, I created successive price drops for my iOS apps to increase downloads and 'publicize' that they will shortly be unavailable; existing users should be able to continue using the app, but new downloads will not be possible.
Starting one year before the ending date of my developer agreement, I lowered the price of each app by one dollar until it was free, and then announced on social media and in iOS music groups on Facebook. Initially this increased downloads by 100x per month, but this became 10x as price-watching platforms like AppShopper shut down.
A clear notice posted at the header of each app homepage explains what will happen so that new users understand.
Hopefully giving it away enables more people to enjoy these apps and find my other projects.
One of the 100 steps to success.