Why won't IMO get installed on my Samsung Galaxy A7?
There shouldn't be any problems when you want to install the IMO application on Samsung Galaxy A7. Try canceling the installation and then switching the network connection to WiFi or Data. Make sure you're using a network that's stable enough then repeat the procedure. I have installed the application on Xperia M2 and it works as it should without errors.
Play Store page: https://play.google.com/store/apps/details?id=com.imo.android.imoim&hl=en