Worries about lawsuit?

I was once worried about getting sued as well. Back then (years ago) when I started freelancing as a sole proprietor (full personal liability, at least in DE) this worry drove me nuts.

It led me to reading up about all the things that a) can go wrong (lots) and b) that actually go wrong so often you hear or read about it (not so many).

Turns out that if you follow some basic rules and do some basic risk management you can massively reduce your risk, no matter if you are a sole proprietor or a behind an LLC. LLC's can easily get sued too btw.

Your individual situation will obviously be very dependent on your country of residence and your business's country of residence, but here' what I'd do to get off the worry train:

1. Make a list of all the things that could wrong and that you think could get you sued. For how much?
2. Research cases where people actually got sued for things that you think might happen. It happens a lot less often than you think. If you read about it, it is definitely big enough of a worry that you should take precautions against that.
3. Take basic precautions, e.g. make sure to have written terms of use, privacy policy, etc. on your website. If your users/clients enter into contracts with you, make sure they are in written form. They don't need to be super perfect (this is not legal advice, btw), but expectations should be very clear (eg.: I do x, you get y, by date z. I will not do a, b, c for you)
4. Expectation management in your copy writing: be careful not to oversell. If you can only deliver, say "99% of availability", don't sell "100% availability".
5. Get insurance. For me personally this helped me the most, the mental assurance that I'd be covered in the worst case. That alone was worth the annual fee. And if you find the right insurance, it also will not be as expensive as you might think :)
6. And, obviously, please find & talk to a lawyer who understands you and your personal situation and can draft default contracts & other paperwork for you.

Personally, I started with a sole proprietorship and switched to Inc when things started heating up.

If you already have some freelance business or other projects you'd like to protect, LLC and branching out other companies into an Inc can make sense too

It’s worth getting an LLC as you can use it for both your app and your freelance work. I’d recommend incorporating as an S Corp or LLC to protect yourself. It’s a cost I absorbed in order to enter the market.

Out of curiosity, how do you collect payments from your users?

From my experience, the vast majority of payment getaways will reject applications if you aren't properly incorporated.