4. Design Guidelinesf you are developing just using an Android phone — switch the android phone into landscape mode (horizontal) and place it to your face (similar to VR mode). There are some differences in IMU between an Android Phone and X1 (see below) but this will enable you to move around your head and simulate AR movement.Background – Make the background screen black – this will make it easier for the user to view information like on phone. Without a black background screen, in high brightness, it may be tough for users to view text. The best color combination is an orange foreground on a black background.Head Movement — Keep user fatigue at a minimum. That means when rotating your head, keep the screen images/text stable and do not have them rapidly change, which would make the user dizzy.Multiple Screens and Increased Development Space — As a developer, utilize the extra screen availability for your app. i.e. the screen size is not limited like for a phone. If users rotate their heads while wearing X1, the users can see different screens, data, etc. You can place data anywhere users will look —- that is the big difference between X1 smart glass and standard Android phone development.API use — Utilize the provided ThirdEye libraries in the way they are documented. This ensures that your app utilizes battery life and the app functions smoothly. If it is natural to nod or select in your app, then utilize those API calls as ThirdEye provides them in the SDK. As a developer, you can save a lot of development time and code your app more efficiently by properly using ThirdEye’s provided libraries.Text Size — Make the text size as large and clear as possible. We recommend 30pixels for Font size. Utilize our ScrollingAPI to scroll. We do not recommend long pieces of continuous text.Scrolling —Use the ScrollingAPI in the ThirdEye SDK.When the user is moving around, you should use larger fonts that are easier to read. You should also display less text overall to avoid distraction and interfering with the users’ view of their surroundings.Icon Size — The minimum recommended icon size is 20×20 pixels so that the icon can be easily recognized by most users. For users who are walking or moving around, we recommend an icon size of at least 60×60 pixels. You can track this via SensorManager. Choose icons that are readily recognizable, so that most users will immediately know what they mean (use standard approved symbols). Be aware that outside light can make icons harder to recognize. Applications intended for outdoor use should make use of brighter and larger icons.Brightness — If certain portions of your app require the user to see the screen text/symbols clearly, we recommend you suggest to users about increasing the brightness (which users would do from “settings”) or to automatically increase brightness in your app by calling that function.