Remove the last_id from File and Project as it's not needed.
Add a default_scope to sort files and projects by their elapsed time
Add a config file, a yaml file to configure watch_tower a section under database/environment should be added to configure the server's database... watch_tower should not be run unless the config file has been edited.
Add a ci/travis.rb script which runs the tests under Travis-CI, needed because the config file added in todo number 3 won't exist and the current setup (sqlite) does not work with JRuby
Figure out how to load assets from gems and remove the bundled jQuery files.
The Config module need some tests.
Convert the Editor module to be Enumerable for easier access to the list of editors
maybe use sinatra-simple-navigation gem
Add tracking by git branch, needs a branches table that belongs to a project and has many time_entries
Maybe use a Rails engine instead of Sinatra ?