The Keeper client program is the same as the one provided by Seafile, the company producing the underlying software of Keeper. So if you happen to see anyone mentioning "the Seafile client", this is the same as the Keeper client and vice-versa.
After downloading the Keeper client program, you have 3 steps left to get it up and running.
1. Select a disk partition to store local Keeper data
Select a path where you want to have your files stored. Any library downloaded will be saved by default here. You can change the path of any library when initially syncing or resynching again.
2. Add an account
Add your (previously created and activated) account. For Keeper please use as the server
https://keeper.mpdl.mpg.de
Your email and password are the same as the one you registered with. Any client will share the same authentication information. If you ended up here while configuring one of the mobile clients and it doesn't work, even though you did everything right, please check the "https" box.
3. Sync a library
- Click the "Sync this library" button to sync it with a local folder.
- Then you add some files into the library. They will be automatically synced with the cloud platform.
4. (Optional) Create a library
You can also create a library from a local folder. The simplest way is to drag & drop the folder to the little area at the bottom of the Keeper client. If you are not sure how it works, just create a smal test folder and give it a try!
Source: Seafile Help