App development

I would like to continue using our existing scheduling sheet, so please review its structure and explain whether any changes would be necessary. Could you please share examples of similar projects, your estimated price and timeline, and any ongoing subscription or maintenance costs? Please also confirm whether your quote includes importing existing data, testing, handover instructions and support for fixing initial bugs. The app should be set up under my business account. I can share the existing sheets so you can assess the work before providing a final quote.