I am using enterprise edition of Salesforce account and I am one of the admin among 6 admins. I have installed an custom app from appexchange but I want to hide the visibility of that app even from other admins. Please let me know the steps if I can do that.
Unfortunately it's not possible with standart same administrator profile, the profile have to have view all access.
But you can clone administrator profile and uncheck view all access. Then with sharing rules, you can limit new cloned system administrator profile.