First, try to do some market research. If you can bootstrap on one platform, you can afford to pay someone to rewrite it later. I'm guessing many potential cust

First, try to do some market research. If you can bootstrap on one platform, you can afford to pay someone to rewrite it later. I'm guessing many potential customers don't have a computer either. Cross-platform is probably a good idea eventually. Including mobile. Since I'm guessing with a note-taking app for confidential information (medical?), your customers might be word-of-mouth. I'm guessing Windows is a good target, but you may want to think about mobile-first. If you go with Windows, Qt is a good choice. But give Electron a shot too, it's probably not that slow for a simple app. It's when people start piling heavy themes and bad algorithms on top of it that it gets slow.