Can you please at least site some of those apps so that it will be more substantial, like what app is that and how they turn out to be a scam. Im sure this will really be a great help, not only for newbies.
for newbie i think using ico rating like coinmarketcap, ico becnh and suggest from pro traders is best way to know. like this find high rating from ico rating site, asking to some poeple, you can combine from this case to get action