You can easily transfer money between your primary bank account and Braid.
To add a bank account:
Tap your profile link in the upper left corner of the app. You'll see a link that says
"+Add Bank"
Then, you'll see a screen that says "Braid uses Plaid to link your bank", and you can follow the prompts to add a new bank account.
After you connect your bank account you can seamlessly make transfers between Compound and your bank account.
The first time you hit "transfer money" you'll be prompted to connect your bank account to Braid. You can connect as many bank accounts as you'd like, and can remove a bank account and add it back at any time.