Best programs to build a mobile app.

You can use Glide to create mobile apps from Google sheets with no-code.
Many people here used it to create their apps .
As they mentioned on their website "Glide turns spreadsheets into beautiful, easy-to-use apps."
https://www.glideapps.com

Adalo for mobile app, Glideapp for quick mobile web app

If you wanted to have someone build your app based on a simple prototype, Figma could be of use. figma.com/prototyping/

You might try out either AppGyver or Builder.ai - both of whom provide really robust no/low code platforms for building native mobile apps. Also if you’re based in Los Angeles there’s a Dev shop called V/One that is giving away their services to 50,000 lucky entrepreneurs (https://techcrunch.com/2020/04/09/app-development-shop-v-one-is-giving-away-50000-free-mobile-app-builds-to-budding-la-mobile-businesses/).

hello, I will answer you depends on my experience and also studying the world market in No-code.

For prototype and layout use InVision or AdobeXD.

But, you know all is depends on the project you intend to develop. You intend to create native App, iOs and android, The coolest platform is thunkable, if it is a web APP with more options and a better tool, Bubble.oi will test it and you will like it.

Good Luck Meeks💪🏿