Club Tally App

I run a club that has promoters get people to come to the club each week and I need to keep a tally on each promoter that brings someone to the club. I have been doing this by paper but want to do it via an App/offline website. I am after something really basic, doesn't have to be visually amazing. Just needs to have all the functions I need to work properly. I am happy for it to be a website that can be used offline or a iphone/ipad app. I created a rough picture of what I want it to look like and what functions I want. I need the app to have a section where I can type in the club night name + the date. It needs to have a button where I can swap between two sheets, one is for the start of the night and one is for the end. The names on the sheets should replicate across but the tally numbers should not transfer across. I want the app/site to display names (that I can add and remove and can add atleast 300 names) and a + and - option to tally up or down to atleast 1000 numbers on each (holding the tally button down does not increase/decrease totals). I want it to display a total at the bottom which calculates the totals on that sheet. I want to have an export option that can export the info via text or whatever to generate in an email to send. I want it to have a reset button, which only resets the numbers on that particular sheet. The reset button should have a 'do you want to confirm - yes/no' dialog before reseting everything. I need the info to save to the app/cache so that if the app is closed/loses an internet connection the results will not disappear. Hopefully this makes sense and let me know if you have any questions. Thanks!