Echo still allows you to install APKs
Originally Posted by Pirateghost
Check this out. . We discovered this in the Paranoid Android Community the other day.
If you have Echo Notifications Lockscreen installed, whether you have it activated or not, it disables installation of apks and the OK button on certain other dialogs. I went nuts trying to figure out what happened...
Echo developer here. You can install APKs by unchecking "use Echo lockscreen"
in the settings. After you install the APK, you can turn Echo back on.
Echo hold a overlay in the background to update the UI whenever a notification arrives. This allows us to be much faster than most apps that only update the UI when the lockscreen appears. During the apk install prompt, google checks whether any overlay exists (thus any screen filter app would disable it too), and doesn't allow the user to proceed if there's one exists.
We are working on a more permanent fix for this issue that retains the smoothness. For now, APK installs work fine when you pause Echo in settings.