This update to Blocks Away is all about privacy. As a free app that displays adverts to cover its costs, there will always be a conflict of interest between total privacy and serving you the most relevant adverts. Now you have a direct say in how the ad networks use what they know about you.
To be clear about our view on privacy — we are not interested in collecting your personal information nor in profiling you, we try to keep collection to a bare minimum — our privacy policy explains all. Apple also provides very good information on the privacy controls available to you — read it here.