[AutoComplex][1] is an Android app that uses "autocomplete" to let the user look up [nondeterministic automaton complexity][2], including proof hints in the form of witnessing sequences of states, of binary strings. So it serves as a database of information about that specific notion of complexity.

 ![Screenshot][3]


  [1]: https://play.google.com/store/apps/details?id=edu.hawaii.math.bjoern.autocomplex
  [2]: http://math.hawaii.edu/home/theses/MA_2013_Hyde.pdf
  [3]: https://i.sstatic.net/ohSvW.png