Fresco
An Android library for managing images and the memory they use
...To save data and CPU, it has three levels of cache; two in memory and another in internal storage. Fresco’s Drawee shows a placeholder for you until the image has loaded and then automatically shows the image when it arrives. When the image goes off-screen, it automatically releases its memory. A decompressed image - an Android Bitmap - takes up a lot of memory. This leads to more frequent runs of the Java garbage collector. This slows apps down. The problem is especially bad without the improvements to the garbage collector made in Android 5.0. On Android 4.x and lower, Fresco puts images in a special region of Android memory. ...