There are no fees for depositing Bitcoin from a third-party wallet onto your Abra wallet. Withdrawing Bitcoin from your Abra wallet onto a third-party wallet will incur a network fee (This fee is required to ensure your transaction is confirmed by the bitcoin mining network and fluctuates based off of volume on the network. Abra does not profit from it. The network fees will be implemented by August 21st, 2017). There are no fees for sending or receiving Bitcoin between Abra wallets. Whenever there is a conversion from Bitcoin to another currency, or vice-versa, we will apply the current exchange rate.
Further information about Abra's fees can be found here.