You can update your stock situation in Zigaflow and this is easily done on a tablet or iPad.
Select:
- Modules
- Stock Control
- Stock Details
On the left-hand side select the stock area you are checking.
If you need to change a quantity, click on the edit button 
Enter the new quantity and any narrative:
Go back to the Stock Overview screen to see totals across all locations.
Here's a video showing how it works: