When you download SelBuk from the Appstore you will see a green icon and a blue one. The green icon is the update version for devices iPad or iPhone where you will registered your active user. The blue version SelBuk-B is used when we ask the users to download it because there is a bug on the green one that might take a little bit of time to be fixed.
So please always use SelBuk green icon either for iPad or iPhone.