Offline screen keyword Detector with on device OCR technology

I want an app that detects a specific word (including special characters, icons) added by me visible on my Smartphone , whether it is in image, video or any possible format (just visible on my phone screen and the app sends me a normal notification with sound and vibration). Also I want this app to require no internet connection to work, no data usage permissions. There should be an option to select the specific app whose screen I want monitored. And an option to add the keywords, special characters to be detected. Also this app should use on device OCR technology too. I will pay only after the app successfully sends me notification for any visible word or special characters on my phone app screen.