Each Android device is different, and different carriers load different apps when you sign up through them. Because of this, there is no standard voice recorder app for Android like there is for iOS. Your device may have an app installed already, or you may have to download one yourself. Look for apps labeled "Recorder," "Voice Recorder," "Memo," "Notes," etc. If you can't find a voice recorder app installed on your device already, you can quickly install one from the Google Play Store. Many recorder apps are free.  Open the Google Play Store and search for "voice recorder." Browse through the list of results to find an app that meets your needs. There are tons of audio recording apps available, some for free and some for purchase. Check out the star ratings to get a quick feel for how popular the apps are. Tap an app to view details, such as user reviews and screenshots. Tap the "Install" button once you've found an app that you want to try. If the app costs money, you'll have to tap the price and pay for it before you can tap "Install." Once you've found or downloaded an app, find it in your App Drawer and tap it to open it up. The App Drawer can be opened by tapping the grid button at the bottom of your Home screen. The recording interface will be different for every app, so the rest of this section is just a general guide. When you launch your new recorder app, you'll generally be taken to the New Recording screen or something similar. The app may open to a list of your existing recordings first. Most Android devices have the microphone at the bottom. Make sure that your hands are not covering the microphone while you're recording. You can usually pause your recording without finishing it, allowing you to resume recording again. This will typically save the recording to your device, but this will vary depending on the app you are using. Most recording apps include basic editing functions, allowing you to trim out unnecessary parts. The Edit button typically appears after you have finished the recording....

TL;DR in Vietnamese:
Tìm ứng dụng ghi âm trên thiết bị. Tải ứng dụng ghi âm từ Google Play Store. Khởi động ứng dụng ghi âm. Nhấn nút Record (ghi âm) để bắt đầu đoạn ghi âm mới. Hướng đầu dưới của điện thoại Android về phía nguồn âm thanh. Nhấn vào nút Pause để tạm dừng ghi âm. Nhấn nút Stop để kết thúc ghi âm. Chỉnh sửa đoạn ghi âm. Chia sẻ đoạn ghi âm.