Hello Marosi

1. Kindly check the user groups in developer mode and check if the users are part of the Sales module by going to settings module and on the menu select groups and companies- groups and search for sales. This should bring a list of sales administrator and sales user groups and open to see if any of the users are part of the list as shown below.

once you add the user on this list, they should be able to see the sales module or any other module

2. To be able to see the app store module, go to settings-users and under the tab Administartot slelect the option to settings as shown below. This will also give you access to see the additional settings of the settings.