You can either connect your portfolio to your exchange account or you can add a portfolio manually.
To add a transaction to your manual portfolio, follow these steps:
Select Portfolio on the bottom of the screen.
Swipe far to the right and tap Add Manual Portfolio (or tap the hamburger icon on top right and select Add Portfolio)
Enter Portfolio Title and Total Cost (optional), tap Add.
Now go to your manually created portfolio and tap Add Transaction
Choose the coin from the list (ex. Bitcoin).
In New Transaction window you will see 2 options - Simple and Advanced .
Enter the amount of your Total BTC.
Select the Exchange where you performed the trade and the correct trading pair.
Enter the date and time you made this transaction.
Enter buy/sell price in Price field.
Enter the amount of Fee incurred in percentage format.
The "Deduct from..." option ("Add to..." when adding a sell transaction) is very useful if you want to reflect changes in your pair currency. For example, let's say you have some BTC already added in your portfolio. Now as you are entering a ETH/BTC buy transaction, if you turn on this option, CoinStats will automatically create a linked sell transaction under your BTC holdings subtracting the corresponding amount of BTC. Note, that since these two transactions are linked, editing or deleting either one of them will automatically edit or delete the other.
Leave Notes for yourself if you wish to and tap Add Transaction.