Really like this window film...very easy to install! We have a dog that likes to “perch” and bark at the world going by so needed to block our front door window so light comes through but no one could see outin. 
I YouTubed how to install window film and best practice was to have a spray bottle of plain dish soap and water and spray entire window as you are installing...this provides some flexibility in maneuvering the film a bit. We also found that by ensuring we had the top left and left side were 100 square (we are both right-handed), rest was easy! We have 4 more windows to do and are going to cut to fit exactly first and try installing that way...seriously, wetting the entire window with the soapwater spray (until it is literally dripping!) gave ability to maneuver a bit with the film. The windows however are not huge (ie not like large living room...these are for a door and kitchen sink that neighbors can see into my kitchen) 
Love it so far!