Contraction timer app

Brandy • 29 yr old SAHW. Endo and 1 ovary; DH had a VR. After 4 failed IUIs, currently Pregnant from 1st ICSI IVF cycle!!!
FTM here looking to get a contraction timer app that lets me see averages over a length of time and perhaps a graph display. Does anyone have any recommendations for what they used? Thanks!