I really like the application, it is unique and probably one of a kind in the store; although Estimation has various ways to calculate scoring according to whom you are playing with, but you keep it flexible to change the scoring settings.
Did not get what you mean with "Enable Insist" though, probably for the same reason, that it is played differently everywhere.
The point I may would like you to take is the too many dialogs pop out to fill in data is somehow irritating and the need to call for the menu every time to proceed to the next step (new game, end round...etc), not sure if iOS avails "buttons" as UI controls or not though!
Also, in case of "all loses" (Se3ayda), down people only adds/deducts 10 in the next round, not necessarily doubling the score.
Overall, it is great. Keep up the good work.