Big picture advice on workflow/starting point

Hey folks -

I'm a former developer (primarily Java) now teaching in high school and working with IT to try to maximize our use of the K12 product. As an active teacher, I'm aware of a number of things I'd like to add/create to help our teachers more easily access the information they want, or to improve workflows. For a very basic example, I'd like to create something that generates a weekly “comprehensive report” for each teacher (attendance stats, missing assignments, ungraded work)… that type of thing. Much of it at first would be passive consumption of data, not any actual manipulation of the core data via the API.

I've dabbled in getting some Google Scripts to connect via OAUTH and snag some data to create custom reports, etc, but I'd like to get to the next level and start work toward one of two things:

• a custom Chrome extension for my teachers to provide quick access to some often requested reports/information. I sometimes think this is the way to go since we're a Google school and staff is largely averse to more “things” to use.
• a very basic app that uses their Google login (we are using Google SSO) and lets me make dashboards (round 1) and possibly quick action screens (round 2) to attempt to give them what they want.

We've failed at using reports to get what we need, and I've somewhat given up on the ideas boards for getting features fixed/changed. Where I'm stuck now is, what's the best environment to start in? Where did others begin when writing custom things (with auth access)? Are there templates? Examples? Have any of you succeeded at similar things?

Any advice would be appreciated! Thank you.

Dave