Also, if at any point you find any of the packages you have previously bought locked (can happen when you reinstall the app), tap on Settings in KetoDiet (the round wrench icon at the bottom - right corner) and then tap «Restore all purchases». (ketodietapp.com)
The new features can be found when adding a filter by selecting the new wrench icon. (androidcentral.com)
It will begin to spin, then a little wrench icon will appear next to it — this is your indicator that the System UI Tuner has been enabled. (howtogeek.com)