Looking for a specific app

( Google / android app ). Heres what I want,,,, I need a basic programme / app that can add & subtract a product quantity for me. We have a small storeroom at work & we currently count & record on paper the ins & outs. So, I start with a full count of product then add newly made & minus sent out goods & do this daily to keep on top of the count. Anyone know of any simple 'ins & outs' apps / programmes. Poss with an email feature ? thanks

Here's a bunch from a simple search on Play Store.
The rest (ie deciding suitability) is up to you.

https://play.google.com/store/apps/details?id=vag.mobile.stockcheck&hl=en https://play.google.com/store/apps/details?id=com.XNRSisbi.stockcontroller&hl=en https://play.google.com/store/apps/details?id=com.soto2droid.facturacion&hl=en

These probably do more than you want, but I doubt anyone is going to create an app with such simple requirements.