> For the complete documentation index, see [llms.txt](https://intowow.gitbook.io/crystalexpress-documentation-v3-x/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://intowow.gitbook.io/crystalexpress-documentation-v3-x/master.md).

# Introduction

![](/files/-LGUa0rkHI2f2FkMYcNf)

### CrystalExpress™ is a solution for brand advertising powered by high-definition, zero-latency video technology. Your app could deliver perfect advertising and user experience by integrating CrystalExpress™ SDK.

### This Documentation applies for CrystalExpress™ SDK 3.x series

![](/files/-LGUa0rm5t-H4qe-KpJV)

## Choice of SDK Versions

There are two versions of CrystalExpress™, which are CrystalExpress™ Lite and CrystalExpress™ Premium. The main difference between these two versions is intelligent placement management.

| Function                                                  | Lite                                                      | Premium                                                   |
| --------------------------------------------------------- | --------------------------------------------------------- | --------------------------------------------------------- |
| Patented predictive prefetch technology                   | v                                                         | v                                                         |
| Dynamic media transcoding optimized for each device       | v                                                         | v                                                         |
| Ad placement supported                                    | Launch screen, interstitial, in-feed, content, and custom | Launch screen, interstitial, in-feed, content, and custom |
| Intelligent placement management & inventory optimization | x                                                         | v                                                         |
| Ad format supported                                       | INTERSTITIAL、CARD、NATIVE、IN-STREAM、REWARDED VIDEO、WEB     | INTERSTITIAL、CARD、NATIVE、IN-STREAM、REWARDED VIDEO、WEB     |
| Platform supported                                        | Android 4.0 and later                                     | Android 4.0 and later, iOS 8.0 and later                  |