What are the best electricity retailer with good apps in Singapore?

Hi there! I am planning to switch from SP to other electricity retailers in Singapore. Having considered all options, I am looking at Sembcorp, Senoko or Geneco because of their low price cum the promotions available. However, I heard from some of my friends that the UX and UI on apps are also a crucial factor when choosing these retailers. Does anyone here have any good/bad experience with their electricity supplier's apps?