You can add any phone number to your Allowed or Blocked lists within the app. Remember, for the best results, ensure you input the entire phone number, for example, +1 555-323-6547.

Here's how:

1. Open the Robokiller app.
2. Choose Settings.
3. Tap on Blocked and safe filters.
4. Select Blocked or Safe, then Numbers, and tap +Add in the top right-hand corner to add the full number.

It's as simple as that! Happy call-managing!