The old adage in the market economy is that, "You get what you pay for".  So, you should be suspicious of anything that is free.  There are a dizzying number of free apps and services.  So, your instinct might be to steer away from them.  That instinct is mistaken, because there are actually some great free services and apps out there.  The challenge is to find them and work out which is worth your time and your hard drive space.  This fantastic Medium item discusses five that are worth your time.   More