For Android users visit the Google Play store and search Hailo Driver. From there you can download and install the app.
For iPhone (iOS) users visit https://new-install.hailocab.com/ and click Download.
Note for iPhone users: If you have a phone running iOS9 you may be asked to trust the Hailo app before you can open it. If so follow these steps:
1) Go to you phone's Settings
2) Go to Profiles
3) Select Hailo
4) Select "Hailo Driver 2"
5) Tap Trust
Once done you can now open the app.