What is the mobile application for my client to access his Quickbooks online account?

You can let your client monitor and access their account using the QuickBooks Online (QBO) mobile app, @aaconsultancy-cs. I'll guide you on how they can download this on their Android devices.

The QBO mobile app is available worldwide. Though your client is in the Philippines, they can download the app to sign in and access their account. To do this using an Android device, here's how:

1. Open Google Play on their device and search for QuickBooks Online. This app works on smartphones and tablets. 
2. Select Install.
3. Since they already signed up for QuickBooks Online, let them use the same user ID and password to sign in to the app.
4. They may be asked to enter a one-time code to confirm their identity. Once confirmed, they can continue into their account.

Moreover, they can also access QBO without an app by using the browser on their device. If you wish to learn more about this, please see this article: QuickBooks Online mobile app.

Also, there are specific QBO mobile app features supported on Android devices. You may want to check out this article to see the available ones for your client: Compare mobile app features.

Please let me know in the comments if you have other concerns about the QBO mobile app and managing your client's account. I'll gladly help. Take care always, @aaconsultancy-cs.