August 2017
September 2017 - last edited September 2017
Go into your phones settings and clear the cache for all apps. That'll free up a lot of space.
If your phone has an SD card consider setting up apps to use it rather than the device memory.
E.g. Apps like camera. You can also move your DCIM folder over to the SD card.
For Android users, if you've never done this before, dial *#9900#
Then select Delete Dumpstate/logcat.
You can save several gigs of wasted space that way. These logs are totally unnecessary.