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
   

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3. Emerging Markets
   Drive Growth
   

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4. Source: Mediacells via The Guardian
   

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5. Source: Mediacells via The Guardian
   

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6. 44
   36
   21
   51
   37
   11
   80
   10
   9
   25
   66
   9
   Smartphone Feature phone Multimedia phone
   Brazil Russia
   India China
   

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7. 1. Optimizing App Size
   

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8. The smaller, the better
   

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9. Color Filters
   

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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.
    

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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 );
    

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12. Image
    Optimizations
    Color Filters
    

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13. JPEG WEBP PNG GIF
    Lossy
    Lossless
    Transparenc
    y
    Animation
    WebP
    

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14. No Noticeable Change
    PNG
    24 kb
    WebP
    10 kb
    

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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.
    

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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.
    

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17. Remove
    Unused
    Content
    Image
    Optimizations
    Color Filters
    

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18. Remove Unused Content
    • Use Resource Shrinking.
    

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19. Code
    android {
    ...
    buildTypes {
    release {
    minifyEnabled true
    shrinkResources true
    proguardFiles getDefaultProguardFile('proguard-android.txt'), 'proguard-rules.pro'
    }
    }
    }
    

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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/
    

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21. 2. Optimizing Network
    Calls
    

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22. Expensive
    Data
    Flaky
    Networks
    Challenges
    

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23. Build for Failure
    

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24. Most efficient way to
    transfer is to not transfer
    

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25. Image Scaling
    

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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.
    

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28. Checksum
    Image Scaling
    

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29. Client A Client B
    Server
    Checksum
    ID
    Send File ID
    Transfer File
    CS ID
    

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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;
    }
    

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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.
    

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32. Image Scaling Checksum
    Transfer in
    Blocks
    

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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.
    

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34. Testing for different
    networks is a pain
    

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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/
    

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36. 3. Optimizing for Differen
    Phones
    

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37. Small Screens
    Slow
    Processing
    Challenges
    

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38. Developing for flagship
    devices is easy
    

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39. Year Class
    

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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
    

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42. Redesign
    Year Class
    

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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
    

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44. @vinaygaba
    Questions?
    

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