Attempt to make first simple app

Hi guys, I'm not sure if this is the correct forum to post on but I'd appreciate any advice you can provide.

I'd like to "have a go" at app design. I have an ideal first project in mind; it's functional, would have a userbase of several hundred people and should be relatively simple in it's design...I just need to find the right tools for making the app!

The brief
At work, we complete paper forms to submit overtime and expenses claims. I want to make an app that allows users to enter the relevant data, then export it into a predefined form at the end of the month in either PDF, XLS or JPG format for printing.

I'm capable of making such a form as a website or in MS Access, but both of those provide compatibility and implementation issues with staff using mobile phones to enter data. I'm not sure if there's a design app that would help me create an Android app for this purpose? Unfortunately, I don't know the first thing about code and although I'd like to learn, this project isn't the appropriate time to do it. I'm under no illusions that it'll take dozens of hours of work to create this app, I just can't invest the hundreds of hours necessary to learn the code to do so.

If anyone can point me in the direction of a GUI style app designer that might work for the above I'd appreciate it. The app won't be monetized.

Thanks,
Andy