NoPlex features a robust and intelligent search feature that's available via a field at the top-center of the web app...

...and the bottom of the mobile app:

When performing a text search, an icon will appear next to each result, indicating whether it's a Task, Note, or Routine. Note that searches that lead you to results related to Routine Tasks will show both the Routine that contains it and any Tasks it's produced. The same goes for recurring Tasks — you'll get results for both the recurring Task and any Task it's produced.

Additionally, if you want some inspiration about a topic to make sure you have all of your bases covered you can browse thousands of ideas within Plexies. You can learn more about Plexies here.