1.The demo has been tested on devices below:
    Google Nexus4-4.1.1-API16-768x1280 (Android virtual device)
    Google Nexus One-2.3.7-API10-480x800 (Android virtual device)
    Meizu MX3-5.0.1-Flyme OS 4.3.2-API21-1080x1920 (Anroid real device)
  I've try to make the layout looks fit on those three major resolution.

2.It will be much better if we can know one image's size in advance, then we can set different place holder image to fit different image size rather than set a fix size to every tweet with single image.

3.The requested API Level is 14+, I set it to 10+, which I think is harmless.

4.The data model structure is easy to add some more complicated cache strategy. Since data caching is not a must in this work, I just implements the basic image caching logic.

5.Some images' url seems to be broken, I can not get them on phones even with under a VPN.