Redemption is a great movie and TV addon for kodi and one of my favourites.
The steps to add an addon which isn’t available in Kodi itself are:
i. Adding a source to Kodi (a url which stores repositories online)
ii. From that source you install a repository (online storage which houses addons, usually grouped together by a team of developers) to Kodi
iii. From the repository you select and add your addon to Kodi.
b. So, Step 1: Adding a Source to Kodi:
i. Open Kodi
ii. Select System > File Manager
iii. Select Add Source
iv. Select the box which says “None”
v. Type the following into that box: http://echocoder.com/repo/ and then select “Done”
vi. Highlight the box below this to name this source and give it a name. Looking at the above URL, call it something like echo, then click “OK”
vii. Click back to your Home Screen (the back arrow on a remote a few times should do this, if you’re unsure, close Kodi and open it again.
c. Step 2: Adding the Repository:
i. Select System>Settings>Add-ons
ii. Select “Install from zip file”
iii. Select echo, or whatever you named your URL in step vi.
iv. Select “repository.echo-x.xx.zip”
v. Wait and after a few seconds, a message will read: “Add-on enabled”
d. Step 3: Installing the Addon:
i. From the same location “System>Add-ons” select “Install from repository”
ii. Select “Echo”
iii. Select “Video Add-Ons”
iv. Select “Redemtion”
v. Select “Install”
vi. After about ten seconds, a message will tell you: “Add-on enabled”