Android support lib v4 or v13 -

i have developed android application build using api 13 , min-sdk api 13. want incorporate swiping across tabs, , purpose using v4 support library.

i have following questions,

1. which support library should use v4 or v13?
2. should change target api 14? more importantly how decide, should targeted api compile against?

for question 1: @stinepike said, depending on use minimum, should use v4 min-sdk = 4-12 if min sdk >=13 ok use v13.

for question 2: best target depends on plan do, if want provide features introduced in higher sdk level, have use higher target-sdk make sure check android version not use android apis introduced in higer sdk version on device older android version

if(build.version.sdk_int >= build.version_codes.honeycomb) {     // safe use api 11 / android 3.0 stuf } else {     // use api level <= 10 stuff } 

for min-sdk same. if require stuff of api level >= 10 have use min-sdk 10

my opinion: don't use api level < 10, not worth it... 10 reach 90% of android devices
my opinion (as of april 2016): don't use api level < 16, not worth it... 16 reach ~95% of android devices

for checking distribution of android os version check: https://developer.android.com/about/dashboards/index.html