I know a few others have indexes of various game elements and a few even have searchable/sortable web forms. I'm tossing mine out there and others are free to use it as a basis for their own tools.
A summary of what's in my spreadhseet:
Overview
- Some notes on the document without as much breakdown on contents of each sheet as on here but useful to know.
Magic Items
- Item Name
- Item Type and sub-type (i.e. weapon / sword)
- Rarity
- Does it require attunement, if so any restrictions (i.e. dwarf, spellcaster)
- Sources found in
Monsters:
- Monster Name
- Size
- Type and Sub-Type (i.e Humanoid - Human)
- Alignment
- AC with notes on what gives it (i.e. natural, plate)
- Hit Points - average and HD
- Movement speeds by type of movement
- Ability Scores
- Challenge
- Environment found in (based on tables in DMG)
- Sources found in
Spells
- Spell Name
- Level
- Classes that can cast it (each class is it's own column for sorting, doesn't include Eldritch Knight or Arcane Trickster)
- School
- Is it a ritual
- Casting Time
- Range (doesn't note if cone, cube, etc. just distance)
- Components (each a separate column, material only lists a Yes/No)
- Does it Use Concentration
- Duration
- Sources found in
Sources
- Source Name (i.e. Player's Handbook)
- Version/Edition, currently 1st for all printed books, and whatever version the latest downloadables are as of today
- Type (i.e. book, pdf)
- How Acquired (purchased for books, hyperlink to latest version for downloadables)
- Version of document added to index
- Version of document last updated in index
I'll be updating it every so often and the Overview page will always note the document version and when it was updated.
As new books and pdfs come out I'll add them to sources and if there's an updated version of a pdf I'll update the hyperlink for it and update the sheets with any changed data. The link is for google docs and is viewable only but should allow you to copy/download it for your own version (just so people don't mess with what I've done accidentally or on purpose).
Here's the link: https://docs.google.com/spreadsheets/d/1HXDqVa4plilwR4DQWJ1KYZUrinC3p5T3Sq8P9Bj76jo/pubhtml
Let me know if I've made any errors (I've tried to double-check but nobody is perfect when proofreading their own material) or omissions. Do note that I'm only including official 5e WotC material which is why so many monsters have no environment data since I only took things from the DMG table which doesn't cover the non-giant versions of various creatures or monsters from the Tyranny of Dragons books/supplements. I did mark the 2 magic items in the Starter Set as "unique" since they didn't have a rarity listed.
Hopefully some people find this useful 
This is excellent! Thanks!
DUDE!
You guys that put your time into stuff like this, for free no less, are awesome.
thanks, and I did it because it's how I best think and I use the index for my own gaming. I started this before the PHB even came out so it's been manageable, just adding a new book/pdf as they're released. I had to reformat it a bit when I put it up on google docs as they don't support vertical text orientation (my original xls file has the environments, classes in the spells tab, and such vertical to make it less spaced out).
Until we have any sort of official digital compendium this should be useful for figuring out where to find stuff though we likely won't have the book/rule bloat that we had in 3.x days heh.
If anyone wants any other categories added let me know. Keep in mind I'm trying to keep this as a quick reference with some sorting, and it's never going to be able to replace the actual material it's pulled from. It's meant just as a way to sort and locate. I'm not sure we need any other categories right now with the small number of sources there are. Maybe once more books come out and there are more items or gods I will likely add those as tabs as well but for now they're almost all in the PHB/basic rules/starter set and mostly overlap entirely.