Безопасен ли theappbuilder.com?

I have been testing a few app builder sites and a lot I have found are very limited in features for the free versions. This site gives access to a lot of features for free with an easy to use interface. It can be a bit buggy on some browsers though. I expect the site to change rapidly, as it is currently in BETA, so at the moment all the options are free, and no ads are displayed within your apps. They do state that once they are ready they will be splitting the site into Free and Paid services. The Free services may end up containing ads, and there may be limitations on features, or how much storage an app can use. All this is disclosed up front. Clean and safe site to use