Droidcon Montreal 2015: Optimizing Your Apps For Emerging Markets

Talk that I gave at Droidcon Montreal 2015 about ways in which you can optimize your apps for markets which are driving the growth of smartphones.

Transcript

1. Optimizing Your Apps For Emerging Markets #DroidconMtl
3. Emerging Markets Drive Growth
4. Source: Mediacells via The Guardian
5. Source: Mediacells via The Guardian
6. 44 36 21 51 37 11 80 10 9 25 66 9 Smartphone Feature phone Multimedia phone Brazil Russia India China
7. 1. Optimizing App Size
8. The smaller, the better
9. Color Filters
10. Use Color Filter • Faster way to experiment with color schemes. • Reduce the number of assets, which in turn reduc the apk size. • Less memory used as the number of assets are reduced.
11. Code ImageView redCircle = (ImageView) findV iewById(R.id.circle_red_imageview); ImageView greenCircle = (ImageView) findV iewById(R.id.circle_green_imageview); ImageView blueCircle = (ImageView) findV iewById(R.id.circle_blue_imageview); // we can create the color values in different ways: redCircle.getDrawable().setColorFilter(C olor.RED, PorterDuff.M ode.M U LTIPLY ); greenCircle.getDrawable().setColorFilter(0xff00ff00, PorterDuff.M ode.M U LTIPLY ); blueCircle.getDrawable().setColorFilter(getResources().getColor(R.color.blue),PorterDuff.M ode. M U LTIPLY );
12. Image Optimizations Color Filters
13. JPEG WEBP PNG GIF Lossy Lossless Transparenc y Animation WebP
14. No Noticeable Change PNG 24 kb WebP 10 kb
15. Compatibility • You can use the native WebP decoder on 4.2 and later. • For lower versions, use libpng to convert to PNG format and then use it in the app.
16. Other Libraries • Use programs like OptiPNG, TruePNG and PNGC to significantly reduce the size of PNG images. • Use mozjpeg for jpeg images. • 5-10% size reduction • Won’t cause any visible changes to the images.
17. Remove Unused Content Image Optimizations Color Filters
18. Remove Unused Content • Use Resource Shrinking.
19. Code android { ... buildTypes { release { minifyEnabled true shrinkResources true proguardFiles getDefaultProguardFile('proguard-android.txt'), 'proguard-rules.pro' } } }
20. Remove Unused Content • Use Resource Shrinking. • Use tools like Lint and ProGuard. • Use Android-Unused-Resources jar file if you are still using Eclipse. https://code.google.com/p/android-unused-resources/
21. 2. Optimizing Network Calls
22. Expensive Data Flaky Networks Challenges
23. Build for Failure
24. Most efficient way to transfer is to not transfer
25. Image Scaling
26. Appropriate Image Size • Store multiple image sizes on the server • Low-res devices might never need a full resolutio image • Most times the smallest image size is sufficient.
28. Checksum Image Scaling
29. Client A Client B Server Checksum ID Send File ID Transfer File CS ID
30. Code public static String getM D5EncryptedString(String encTarget){ M essageDigest mdEnc = null; mdEnc = M essageDigest.getInstance("M D5"); // Encryption algorithm mdEnc.update(encTarget.getBytes(), 0, encTarget.length()); String md5 = new BigInteger(1, mdEnc.digest()).toString(16); while ( md5.length() < 32 ) { md5 = "0"+md5; } return md5; }
31. Checksum • Avoid transfers as much as possible. • For file transfers, first compute the md5 checksum and send it to the server to check if it already exis on the server. • The cost to upload the entire file again can be avoided.
32. Image Scaling Checksum Transfer in Blocks
33. Transfer in blocks • Do data transfers in blocks. • Keep track of the blocks that have been transferre and yet to be transferred. • The block size can vary based on the type of connection.
34. Testing for different networks is a pain
35. Testing for different networks • Facebook recently open-sourced Augmented Traf Control (ATC). • It is a tool to simulate network conditions. • It can simulate 2G, Edge, 3G, and LTE networks. • Has multiple profiles for a lot of different countri http://facebook.github.io/augmented-traffic-control/
36. 3. Optimizing for Differen Phones
37. Small Screens Slow Processing Challenges
38. Developing for flagship devices is easy
39. Year Class
41. Code int year = Y earC lass.get(getA pplicationContext()); if (year >= 2013) { // Do advanced animation } else if (year > 2010) { // Do simple animation } else { // Phone too slow, don't do any animations } https://github.com/facebook/device-year-class
42. Redesign Year Class
43. Redesign • Remove features from low-end devices if they wo have the best user experience. • This could be animations, videos or even functionalities. • No feature >>> Bad feature
44. @vinaygaba Questions?