Sort by most used. Alphabetical sort is case-insensitive.

The most used apps are calculated by incrementing a counter (in a shared
preferences file called launch_history.xml) each time an app is launched
via FAST. Also changed the alphabetical search to be case-insensitive.

Changed 'most popular' to 'by usage'
Merge branch 'master' into new-feature/sort-popularity-updated
Fixed issue with uninstalled apps causing cache to be rewritten and overwrite the call count.
Merge pull request #37 from pserwylo/new-feature/sort-popularity-updated

Sort by most used. Alphabetical sort is case-insensitive (Rebased and Updated)