if you have a carrier specific phone, their pre installed bloatware takes up a fare amount of that 8 GB. Not to mention all the pre installed bloatware from the phone manufacturer. So you're looking at close to 3 GB already gone and you do not have access to it. Honestly, a phone with only 8 GB these days is not gonna allow too much wiggle room to install anything without seeing that "storage running low" pop up.