Internet speed through the TOR anonymization network is much slower than through a non-tunneled connection.
SimpleTOR uses the TOR distributed networks, but is produced independently from the TOR anonymity software and carries no guarantee from The TOR Project about quality, suitability, or anything else.
TOR proxy does not function in China, Iran, and other locations that actively block TOR with DPI (Deep Packet Inspection) technology. Internet providers who use such filtering and censorship technology may also prevent it from working.
SimpleTOR is only a graphical user interface, and it doesn't have any relation with The TOR Project.