Interest will be deposited directly into your app. It is calculated from Friday 05:00:00 UTC to Friday 04:59:59 UTC and distributed on Mondays. This means if your first deposit is on Friday, Saturday, or Sunday your first interest distribution will be the following Monday (you will not receive interest the first Monday).
You can choose to earn interest in-kind, meaning that if you deposit BTC you will earn more BTC, ETH on ETH, XRP on XRP, etc.
You can also choose to earn interest in CEL tokens* at a higher rate, meaning that if you deposit BTC you will earn interest in CEL at a higher rate. You can learn more about this here. You can choose to earn CEL on each coin you hold individually, so if you hold BTC, ETH and XRP you can choose to earn in CEL on your BTC, ETH on your ETH and XRP on your XRP. Full flexibility.
*Earning in CEL not available in the US.