How to clean out your iPhone's memory: Delete the Safari cache
We're going to start by cleaning out the caches on our iPhone. Note that this will mean you're logged out of any websites you've signed into, though. Follow these steps to clear out the Safari cache:

Press Settings > Safari.
Scroll down and tap Clear History and Website Data.
Tap Clear History and Data.
How to clean out your iPhone's memory: Remove file data
Data stored by other apps can be cleaned using the Usage option in settings. Follow these steps to clean out unwanted data from iOS:

Tap Settings > General > Storage & iCloud Usage
Tap Manage Storage.
Tap an app taking up a large amount of storage.
Take a look at Documents & Data - if there's over 500MB of documents in the app, it may be worth deleting it and reinstalling it to clear the extra space.
Simply tap Delete and head to the App Store to re-download it.

OR use the app cleaner instead

Unfortunately there are none that true clean like Android app does. If Jailbreak then iCleaner is a 100% cleaner.

Anyone here using or use turbo sim before? What's the cons?

New Turbo Sim now no need to go through steps. Just plug and play. All I know is it won't work in iOS 11 and up while any version on iOS 10 will work though. Wonder if the new turbo sim still have the problem with No Service due to changing antenna when on the move.

What's your ios version and MY set?

Ah dang. I'm looking for 9.0.2 or below to jailbreak. Since 9.3.3 and 10.2 are kinda not stable.
Good luck with your sale

No can't do, Apple already signed the previous version so no more downgrade available.

I'm getting the iphone 6S for my wife in today's clearance. Upgrading from iPhone SE. Anyone coming?

Same as Machines website

Only ex-demo for 6s / +

Last year also bought demo set. Still great though.