A development journal is a great way to keep track of work done, tasks outstanding, and the learning that happens in projects. You should keep one!
Single-page web apps are awesome, but lack a native implementation for analytics engines. With a little work, Ember can give you the analytics you want.
Ember and Ember Data don't have the greatest dirty state tracking, but you can easily add it in yourself. Don't lose your form data!
Before you start thinking about funding and development, make sure your app idea is as good as it could be.
Google Sheets and Google Apps Scripting are powerful. Using them to build an uptime monitor is awesome and free!
You think that building the app is the hardest part? Deployment and management can be too. Make sure you do it right and provide a great experience.