Google, Apple and Microsoft have been making a lot of security-related changes in the OSes in the last few years. The result is that a lot of apps need updating or just no longer work.
It's not an issue for apps that are actively developed -- but it's devastating for side projects or open source apps that rely on volunteers.
Some changes (like new code signing requirements) might be possible to implement in a few days, but if you need to make bigger changes you are quickly looking at weeks of development time -- which is kinda hard sell for people who develop software in their free time.
It's really killing my enthusiasm for mobile phones that all my old apps are stopping working. My sleep alarm and Tasker screen blocker fell prey to permissions/battery saving issues, and Swype and a few others shut down.
It's not an issue for apps that are actively developed -- but it's devastating for side projects or open source apps that rely on volunteers.
Some changes (like new code signing requirements) might be possible to implement in a few days, but if you need to make bigger changes you are quickly looking at weeks of development time -- which is kinda hard sell for people who develop software in their free time.