converting on premise sharepoint 2013 to provider hosted app tool for office 365

I am looking for tool that does-

converting on premise sharepoint 2013 to provider hosted app tool for office 365. We have 20+ web parts written all in server side code and want to move them to office 365 based system.

I think there is one third party company which is building this conversion tool but I do not remember the name.

Also as per few tweets although sandbox is depreciated it still works in office 365 if you are just playing with list data.

MCTS Sharepoint 2010, MCAD dotnet, MCPDEA, SharePoint Lead