On the website, all you have to do is press and hold the letter. This will bring up a choice of tones for you. 

To input pinyin tone marks on your iPhone, you need to add a Chinese keyboard in your iPhone's settings. You can do this by going to:

Settings > General > Keyboards > Add New Keyboard.

This is because the regular keyboard doesn't have the third tone.

After you switch to a Chinese keyboard, press and hold on a vowel to see all 4 tones, as shown below:

If you have an Android phone (our app is still in the Beta testing phase for Android), you will need to download a pinyin app to support that alphabet.

Installing a keyboard on an Android device:
Android users will have to download an additional app in order to type in Chinese and do a bit more work, but the process is still quite simple.

1. In the Google Play store, search for and download the “Google Pinyin Input” app to your device.

2. Once installed, pop on over to your phone’s “Settings” and select “Language & input.”

3.Under “Keyboard & input methods” select “Current Keyboard.” This will likely be “English (US) – Android Keyboard.”

4. Select “Choose Keyboards.”

5. Look for “Google Pinyin Input” under the list of keyboard and input methods. Switch it on.

6. When you go back to “Keyboard & input methods,” you’ll notice that there’s now a tab for Chinese. From there, you’ll find a ton of settings and options to choose from, but for the sake of simplicity, leave those settings as-is.

7. Go to an app that uses a keyboard. Select the little globe on the left side of your keyboard.

8. There’ll now be a 中 (Zhōng) — China and EN tab. Select the “中” tab.

9. Select the “QWERTY” layout, as it’s the easiest to use.

That’s all for Android users! Like the iPhone, you can switch between keyboards using the globe icon on your Android device.