A sign-up bonus refers to an offer that casino gives to new customers once they sign up on their site. Casinos use these bonuses to attract new customers and provide them with some funds to start betting. Sign-up bonuses are not withdraw-able and should be used within a timelimit, depending on the casino.
Gibraltar is something of a curiosity in Europe. Geographically a part of Spain, it is actually a British territory. Strategically important for the UK, it is also a popular tourist destination. Gambling is legal and popular, and mobile casinos bring a completely new level of convenience for locals looking for opportunities to play.