A free app for Android, by hongthuanjsc.

Ai File Viewer is a very simple and straightforward tool you can use to open and view .ai files – otherwise known as Adobe Illustrator Artwork files – because this particular format cannot open with the typical image viewer.

There’s very little noise, very little gimmick, and very little unnecessary extras in this app. It goes straight to the point of letting you access an Adobe Illustrator piece without the usual hindrance or obstacle one may get from other viewers.  In addition, the app gives you the ability to zoom in and out, as well as drag objects or files. It supports graphic files. It also renders previews through a display window.

Aside from this, the app supports resizing AI images without losing the quality.