For anyone curious about the first change I mentioned, new reports (with both LAN and cloud options available), I'm ready to share some progress on that. If you want, you can try that out by manually updating your app and following a couple other instructions:
- Update the app code: Under Apps Code, update your copy of Device Activity Check by copying/pasting or importing the following code: https://raw.githubusercontent.com/RMoRobert/Hubitat/master/apps/DeviceActivityCheck/deprecated/DeviceActivityCheck2.groovy
- Enable OAuth: Select OAuth, select Enable OAuth in App, and then select Update.
- Re-initialize the app: Navigate to Apps, open Device Activity Check, and simply select Done at the bottom (repeat if you have multiple instances, though the intent of the app is for you to really only need one...).
If you open the app again, you should now have LAN and cloud report links towards the bottom of the app. LAN is recommended unless you need other access. Either should take you to a report page with the same information as the "View current report" page, except this lives outside the regular app UI (and communicates to it using some HTTP endpoints, hence the need to enable OAuth above). I'm leaving the "old" page available for now, though it may be removed at some point if everyone finds the new pages a good replacement.
I'm still working on the second change I mentioned, separate child apps for each "group," ideally without the need to re-create everything to make in-place upgrades easier, but no updates on that yet. 
Just a sort of preview/beta for now in case anyone wants to try!
