If you're having trouble opening the RoboKiller app and getting into your account, or it appears to be indefinitely loading, we suggest deleting the app from your phone, rebooting your phone, and then reinstalling the app.
Don't worry, you won't lose any numbers or data saved in the app by doing so, and you won't be charged twice. Upon reinstalling the app, you'll simply need to enter your phone number and complete the prompted set up. You should then be able to access the app without any issues.
Here are some links that might help:
How to delete apps on your iPhone: https://support.apple.com/en-us/HT207618
How to delete apps on your Android: https://support.google.com/googleplay/answer/2521768?hl=en