Glide – Create a mobile app from a Google Sheet in 5 minutes (glideapps.com)

"The founders of Glide, a member of the Y Combinator Winter 2019 class, had a notion that building mobile apps in the enterprise was too hard. They decided to simplify the process by starting with a spreadsheet, and automatically turning the contents into a slick mobile app." - techcrunch.com

Well done! It seems like a very specific niche, but if you think about it, it covers many types of apps.