Hi @nparajul – You should be able t use IAV with your Java/Android app as well inside of a WebView. At the moment there is no way to do it entirely through a backend server.
There’s other ways you can verify a funding-source too.
One of them is adding a funding-source using the API and verifying it using microdeposits. You can find a guide in our docs here - https://developers.dwolla.com/guides/micro-deposit-verification#verify-a-bank-account-with-micro-deposits
You can also verify banks using Plaid. We have a tokenized integration with Plaid that allows you to seamlessly add a verified funding-source to a Customer account. You can find more info here - https://developers.dwolla.com/guides/plaid
Hope that helps! Let me know if you come across any questions!