What is better? Saas or a Mobile app.

What's better is probably to start with the market first, and gain an understanding of the customer you're serving, the problem they'd find it valuable for you to solve, and the channels through which you're best positioned to reach those customers given their habits + your skillset and budget + the competitive landscape.

Then work backwards from there to figure out the type of product you're going to build. Ideally one that fits into the puzzle piece-shaped hole you just carved out.

It'll be a lot clearer by this point whether you should build SaaS, a mobile app, or something else.

Trying to decide on SaaS vs mobile without doing the above is akin to asking the doctor for a prescription without telling him what your condition is. Maybe you'll get a pill, but do you really want to swallow it?

It depends on the biz/idea. In general, most people here would vote for "SaaS".

Unless you're going to see a lot of in-app purchases/rely on a subscription model, stick to SaaS. That's where the money is.