add a string constant for downloads key
add a string constant for downloads key
ycaihua/skim-app,WoLpH/skim,ycaihua/skim-app,ycaihua/skim-app,WoLpH/skim,WoLpH/skim,ycaihua/skim-app,WoLpH/skim,WoLpH/skim,ycaihua/skim-app