Requiring someone who is spending their resources to provide a price to you to submit it in a certain manner or in an "app" will not happen. You need to make your own spreadsheet,

Hi, HU,

I don't know the conditions in your market, but remodelers in most markets have a backlog of work. You may not be able to get any to bid on your project. A true competitive- bid process requires you provide each with a set of detailed plans and specifications. The more restrictions you put on them--like submitting bids in a particular format or using particular software will surely limit the number of companies willing to bid.

Not a chance in the world that you would get 1 person interested. Unless they are new and stupid. Pitting contractors against each other like you are running a dog fighting ring is no longer close to being an acceptable way to start a project. Just like dating, you are trying to find a partner with the right skills, schedule, and personality, not an adversary.