Say Hello in Swahili

Without any ado, this book sets to let you know that 'Jambo' does not mean 'hello' in Kiswahili. Never mind how many times you might have heard that 'Jambo' means 'hello'. (Truth be told, 'jambo' may be stretched to mean 'hello', but with a lot of caveats). Simply put, you may not want to showcase your (lack of) Kiswahili 'prowess' by greeting a fluent Swahili speaker with a 'jambo'. So, what should be used to say 'hello' in Kiswahili instead of 'jambo'?