A: Waveapps and our platform offers many similar features but we cover some use cases that waveapps didn't cover at the time i checked. Back then it didn't support recurring invoicing, multiple business profiles for managing your different businesses, an estimating system, multiple tax etc.
Plus i think we have a better UI but then again it's subjective. If you're interested, i would suggest you to sign up a free or trial account and check it out and see if it fits your needs. I feel like we generally have a different approach from waveapps in terms of implementing some features.