I have to agree with @tony here, and Twidlit is just such a stand-alone app.
"What type of data do you think we need to collect and share?"
Twidlit measures chord times (not the buttons) because the difficulty of a button depends on what the other fingers are doing (particularly the adjacent ones). By prompting for chords directly (using images), Twidlit removes the problem of the time contribution of remembering which chord to press for a keystroke.
Along with improved skill, the result of practising Twidlit's random chording is a data set of times for every thumbless chord. With a complete data set as a text file, basic Unix command line tools can deliver all kinds of answers.
# strip the standard Twidlit times file to a list of chords with times
grep -v '#' my.timed.right.chords | cut -d' ' -f1,2 > timed.chords
# sum the pinky chord times (using 4finger chord syntax)
grep "^...[',-]" timed.chords | cut -d' ' -f2 | paste -sd+ - | bc
# sum the index finger chord times
grep "^[',-]" timed.chords | cut -d' ' -f2 | paste -sd+ - | bc
echo "scale=3; $pinky / $index" | bc
I get 1.020, so for me (surprisingly), there is only a 2% difference between index finger and pinky times. Where are the big differences?
At this point I have to admit that I find poking around like this with Unix tools to be one of life's simple pleasures. If regex syntax makes your head spin or you simply prefer to use software that has consumed uncountable professional lifetimes then you can perform similar analyses using your favorite spreadsheet and get pretty graphs as well. For now, here we go on the command line using this script:
# gets the average time for a chord pattern
grep -h "$1" "$2" | cut -d' ' -f2 | paste -sd+ - | bc
grep -h "$1" "$2" | wc -l
echo $sum / $count =
echo "$sum / $count" | bc
We can use it to see what happens as adjacent fingers get spread across the keypad:
$ chordavg.sh "'''" timed.chords
7682 / 7 = 1097
$ chordavg.sh "'-'" timed.chords
12124 / 8 = 1515
$ chordavg.sh "','" timed.chords
13347 / 8 = 1668
And how about the number of buttons:
# remove the idle fingers
$ sed 's/|//g' timed.chords > timed.buttons
# 1 button chords
$ chordavg.sh '^. ' timed.buttons
9547 / 12 = 795
# 2 button chords
$ chordavg.sh '^.. ' timed.buttons
72176 / 54 = 1336
# 3 button chords
$ chordavg.sh '^... ' timed.buttons
195228 / 108 = 1807
# 4 button chords
$ chordavg.sh '^.... ' timed.buttons
183772 / 81 = 2268
Is that the kind of data we're after? Download Twidlit and generate your own.