You don't mention which app you are referring to, but it's possible to give you some general ideas. First, you must understand that there no such thing as free, particularly with offers from the internet. If this is a free product, you can rest assured that the distributor will collect information on how the app is used, the data it gathers, as well as personal activity patterns, and sell that information for a profit. This is usually spelled out in the agreement you receive when you download the app. Most people never read these and have no idea what is being collected behind the scenes. It is not insignificant. Second, if it is a product that you must buy, there will likely be less information collected, but unlikely that nothing is gathered. Again, this will be spelled out in the license agreement included with the product. Read it before you buy. In today's society, it is rare that people don't download app's and never read the agreements they come with. Most people disregard it completly! However, if you have any concerns about the product you are considering, read the agreement. If it sounds like they are collecting too much information for your personal comfort, move on!