Yes. Transactions are viewable in the Wallet/Savings section of the GasBuddy app.
To view your transactions, open the GasBuddy app, tap the wallet/savings button, then View Transactions.
Depending on the merchant, the transaction receipt will normally be available within minutes or days from completing the transactions. To ensure you see your transaction details immediately after you're done filling up, elect to receive a paper receipt from the pump.