I have read the HELP topic on performance but I find the information a bit vague. I understand different phones and tablets and different versions of Android can make a difference.

One possibility would be to have some sort of Ultimate To-List performance index. Perhaps the developers could have a comparison for several different generation devices so one could get a rough idea of where one might begin hit performance bottlenecks depending on the approximate performance specs of your device.

Potentially one could have a performance test that one downloads and runs on your machine to evaluate its capability.

Another possibility would be a tool that examines the actual Ultimate To-Do list database in use on a machine and reports on its integrity and any issues developing that might affect performance, e.g., numbering folder items, unusually large number of tags, damaged indices, etc.

Perhaps for a $5 app that's just a task manager such tools would be total overkill. OTH, it's been suggested that there might be an option to selectively trim features from a running UTL install to boost performance. Performance tools might allow you to quantitatively tell if you actually getting any benefit out of eliminating optional features.