I'm thinking of using the Paybis wallet to buy Bitcoin, but I also want to be able to send small amounts to friends. Does the app allow sending Bitcoin to external addresses, or is it just for holding?

Yes, you can send Bitcoin to any external wallet right from the app. I've used it to pay a friend for dinner – just tap "Send", paste their address or scan their QR code, enter the amount, and confirm. The fees are reasonable and the transaction shows up on the blockchain quickly. You can download the app at https://apps.apple.com/us/app/paybis-wallet-buy-bitcoin/id1584641245 and try it with a small amount first. Works for Ethereum and USDC too. It's not just a holding wallet – it's a full crypto wallet with send/receive features.