Everytime I launch the showtime app, it crashes and goes back to the roku screen. I have tried removing and re-installing, rebooting, I was able only one time to get to the login screen but then it crashed when I hit submit. And it keeps doing it repeadtedly.
After removing a channel, best practice is to restart your Roku to clear its memory cache before reinstalling the channel. Without the restart you may not get a clean reinstall.
Depending on your Roku model and Roku version number you'll find the System restart option under either Settings > System > Power or under Settings > System.