I can suggest using mew wallet because, in that wallet, you can save all of the tokens that you earn from the bounty. it is safety wallet as long as you can keep your private keys and not telling other people about this. but if you want to hold your coins, it is better to use the other wallet and I prefer to use offline wallet like jaxx, coinomi, or the other wallet that can save our coins. but you can also use the exchange to save your coins if you want to do fast trade and then you can send it back to your offline wallet.