Protip: install the Xposed Framework on your device, afterwards EnhancedToast to do exactly that.
The Android version of the new app is available here: https://play.google.com/store/apps/details?id=com.imaginationroom.offlinereader
The iOS version is still under review, it could take up to 14 days, once completely we will have a download link in /r/offlinereader subreddit.
This app monitors reddit for specific terms and keywords. It only shows the partular post with the searc term or keyword (I.e not the whole thread) so it might be what you need.
https://play.google.com/store/apps/details?id=smugcat93.monitorforreddit