Merge pull request #12 from fuqcool/dev

Merge Dev
Merge pull request #13 from fuqcool/dev

bring to front on restore
Merge pull request #14 from fuqcool/dev

merge zen-typing and doc
Create datetime.md
Update datetime.md
Create wallpaper.md
Create calculator.md
Create calendar.md
Create googlemap.md
Create weather.md
Update wallpaper.md
Delete weather.md
Create weather.md
Merge pull request #15 from fuqcool/dev

Doc
document