There are several ways, you can give access to the Accorto TIme+Expense application to users:
In general, it is suggested to create custom profiles to manage access.
Global (Profile) Access
When installing, select the "Install for All Users" option:
This updates all your custom profiles.
You could also select Specific Profiles.
In both cases, users only are able to see the application, if they are assigned a license.
> Setup > Installed Packages -- Manage Licenses link for Accorto T&E Plus
Accorto provides also Permission Sets
> Setup > Permission Sets
- Accorto T+E Administrator
- Accorto T+E User
You can assign Permission Sets also from the Users page.
If users experience access issues, you could fix this in the Profile, or assign a Permission Set.