To open an account, you need to already have an account at Pepper Bank (the accounts are linked). Once you do, getting started on Pepper Invest is just a few clicks.
Trading options are extremely limited. There are only US stocks, no ETFs, and a lot of US stocks are missing (I couldn't find Beyond Meat or Checkpoint for instance). UPDATED TO ADD: only S&P100 companies are tradable.
Trading is free (minimum trade amount 50 shekels), but there's a quarterly charge of 0.2%. That adds up to a 0.8% annual management fee, which is pretty hefty, but depends how much you're investing and your investing style. For amounts less than 30,000 shekels this will be cheaper than opening up an account at an Israeli brokerage, and the fee structure here is suitable for people who want to actively trade US stocks (as there's no trading fee).
Taxes are deducted automatically, which is convenient, as it saves you from reporting requirements. (N.B. the 10-year Oleh exemption may exempt you from these taxes though, as the stocks are foreign.)
TL;DR: potentially useful for small scale active traders, but not for large-scale or passive investors.
